Fixed isolator and method for isolating a system

Abstract

To provide a locking isolator and a method of selectively attenuating vibration by using the locking isolator.SOLUTION: A locking isolator 100 includes one or more joints 102. The one or more joints 102 are configured to transition between a clearance fit state and an interference fit state in response to a change in temperature. The locking isolator 100 includes a dampener 104. The dampener 104 is configured to attenuate transmission of vibration through the one or more joints 102 when the one or more joints 102 are in the clearance fit state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates generally to the use of isolators in connecting one structure to another, and more particularly to locking isolators and methods of using locking isolators to selectively dampen vibrations. [Background technology]

[0002] Certain equipment is sensitive to shock and vibration. The functionality of such equipment may be disrupted by relatively strong shock and vibration forces. In high energy environments, it may be desirable to isolate such equipment from the support structure. However, in low energy environments, it may be desirable to securely fasten such equipment to the support structure. Conventional shock and vibration absorbers are only capable of attenuating forces between the support structure and the equipment, but are unable to fasten the equipment to the support structure. Separate fastening devices may be used to selectively fasten the equipment to the support structure. However, these fastening devices may be cumbersome and prone to failure. Accordingly, those skilled in the art have continued research and development efforts in the field of shock and vibration attenuation, and therefore, an apparatus and method intended to address the above identified concerns would be useful. Summary of the Invention

[0003] The following is a non-exhaustive list of embodiments of the presently disclosed subject matter, which may or may not be claimed.

[0004] In one embodiment, a static isolator is disclosed that includes one or more joints configured to transition between a clearance fit state and an interference fit state in response to a change in temperature, and a dampener configured to damp transmission of vibration through the one or more joints when the one or more joints are in a clearance fit state.

[0005] In another embodiment, a rigid isolator is disclosed that includes a base, a linkage coupled to the base, and a cap coupled to the linkage opposite the base. The rigid isolator includes a damper coupled to the base and the cap. The linkage is configured to transition between an unlocked state in which the cap is movable relative to the base and a locked state in which the cap is locked relative to the base in response to a change in temperature. The damper is configured to dampen transmission of vibrations between the base and the cap when the linkage is in the unlocked state.

[0006] In one embodiment, the disclosed method of isolating a first structure from a second structure includes the steps of: (1) coupling the first structure and the second structure together using a fixed isolator; (2) transitioning one or more joints of the fixed isolator between a clearance fit state in which the first structure and the second structure can move relative to one another and an interference fit state in which the first structure and the second structure are fixed relative to one another in response to changes in temperature; and (3) damping the transmission of vibration between the first structure and the second structure using a damper of the fixed isolator while the one or more joints are in the clearance fit state.

[0007] Other embodiments of the disclosed systems, apparatus, and methods will become apparent from the following detailed description, the accompanying drawings, and the appended claims. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic block diagram of one embodiment of a stationary isolator. [Diagram 2] FIG. 2 is a schematic perspective view of one embodiment of a stationary isolator. [Diagram 3] FIG. 1 is a schematic elevation view of one embodiment of a system using fixed isolators. [Figure 4] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Diagram 5]FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 6] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 7] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 8] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 9] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 10] FIG. 1 is a schematic diagram of one embodiment of a fixed isolator piezoelectric generator. [Figure 11] FIG. 2 is a schematic cross-sectional elevation view of one embodiment of a stationary isolator. [Figure 12] FIG. 1 is a flow diagram of an embodiment of a method for isolating a system. [Figure 13] FIG. 1 is a flow diagram of an aircraft production and service methodology. [Figure 14] 1 is a schematic block diagram of an embodiment of an aerospace vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following detailed description refers to the accompanying drawings, which illustrate specific embodiments described by the present disclosure. Other embodiments having different structures and operations do not depart from the scope of the present disclosure. Like reference numbers may represent the same features, elements, or components in different drawings.

[0010] Illustrative and non-exhaustive examples of subject matter according to the present disclosure that may be claimed but may not be claimed are provided below. Reference herein to an "example" means that one or more features, structures, elements, components, properties, and / or operational steps described in connection with the example are included in at least one aspect, embodiment, and / or implementation of the subject matter according to the present disclosure. Thus, the phrases "an example," "another example," and similar phrases throughout this disclosure may, but do not necessarily, refer to the same example. Furthermore, subject matter characterizing any one example may, but does not necessarily, include subject matter characterizing any other example. Furthermore, subject matter characterizing any one example may, but does not necessarily, be combined with subject matter characterizing any other example.

[0011] The present disclosure recognizes that certain structural systems include functional equipment that is sensitive to shock and vibration but also needs to be securely fastened during operation. For example, many aerospace vehicles include equipment that is sensitive to shock and vibration, such as communication arrays, guidance systems, vision systems, star trackers, etc. During periods of relatively strong shock and vibration forces, such as during the launch of a spacecraft or the takeoff / landing of an aircraft, it is beneficial for the system to provide flexibility between the support structure and the equipment, as well as to absorb the transfer of shock and vibration from the support structure to the equipment. During periods of relatively weak shock and vibration forces, such as during the operation of the equipment, it is beneficial for the equipment to be securely fastened to the support structure.

[0012] The present disclosure also recognizes that conventional solutions for isolating structures of a structural system include simple isolation devices that absorb or dampen shock and vibration between the structures. However, these simple isolation devices are unable to provide stiffness between the structures in situations where stiffness is needed or desired. In such situations, clamps or similar fastening devices can be used to provide the desired stiffness. However, these fastening devices are typically complex, heavy, controlled by a computer, and require external power for operation. For these reasons, conventional isolation and fastening devices may be disadvantageous in various situations in the aerospace industry.

[0013] 1-11 , by way of example, the present disclosure is directed to a rigid isolator 100. Embodiments of the rigid isolator 100 selectively isolate vibrations between structures in certain environments while securing the structures together in other environments, without requiring the combination of conventional separate vibration isolators and securing devices described above.

[0014] With reference to FIG. 1, in one or more embodiments, a stationary isolator 100 includes one or more joints 102 configured to transition between a loose fit state and an interference fit state in response to changes in temperature.

[0015] As used herein, a "loose fit" in reference to one or more joints 102 refers to a condition in which a space or gap exists between the contacting or mating portions of the joint. A loose fit provides a loose connection with some slack and allows the mating portions of the joint to move relative to one another. In other words, when in a loose fit condition, the joint allows relative movement between the mating portions of the joint.

[0016] As used herein, an "interference fit" in reference to one or more joints 102 refers to a condition in which an interference fit exists between contacting or mating portions of the joint. An interference fit provides a tight connection with no slack and in which the mating portions of the joint cannot move relative to one another. In other words, when in an interference fit, the joint inhibits or restricts movement between the mating portions of the joint.

[0017] For purposes of this disclosure, the phrase "change in temperature" may refer to a change in the ambient temperature surrounding one or more joints 102, a change in the temperature of one or more joints 102 themselves, a change in the temperature of one or both mating portions of one or more joints 102, or any combination thereof.

[0018] In one or more embodiments, the one or more joints 102 of the fixed isolator 100 include a plurality of joints 102. The plurality of joints 102 are coupled together. Each of the plurality of joints 102 is configured to transition between a clearance fit state and an interference fit state in response to a change in temperature. In one embodiment, the one or more joints 102 include two joints 102. In another embodiment, the one or more joints 102 include three joints 102. In other embodiments, the fixed isolator 100 includes any number of joints 102 (e.g., four or more).

[0019] In one or more embodiments, the rigid isolator 100 includes a linkage 124. In one or more embodiments, the linkage 124 includes one or more joints 102. In one or more embodiments, the one or more joints 102 of the linkage 124 include a plurality of joints 102. Each of the one or more joints 102, such as each of the plurality of joints 102, forms a point at which an articulation link of the linkage 124 is joined. In one or more embodiments, the linkage 124 is configured to transition between an unlocked state, in which the articulation links of the linkage 124 are movable relative to one another, and a locked state, in which the articulation links of the linkage 124 are locked relative to one another, in response to a change in temperature.

[0020] For purposes of this disclosure, the term "unlocked state" with reference to linkage 124 refers to a state in which one or more joints 102, such as at least one of the plurality of joints 102, are in a loose fit state. In other words, in the unlocked state, linkage 124 is flexible.

[0021] For purposes of this disclosure, the term "locked state" with reference to linkage 124 refers to a state in which one or more joints 102, such as each of the plurality of joints 102, are in an interference fit. In other words, in the locked state, linkage 124 is rigid.

[0022] In one or more embodiments, the stationary isolator 100 includes a dampener 104. The dampener 104 is configured to attenuate the transmission of shock and vibration through one or more joints 102, such as at least one of the plurality of joints 102, when the one or more joints 102, such as at least one of the plurality of joints 102, are in a clearance fit condition. In one or more embodiments, the dampener 104 is coupled to one or more joints 102, such as the plurality of joints 102.

[0023] In one or more embodiments, the snubber 104 is configured to dampen the transmission of shock and vibration through the linkage 124 when the linkage 124 is in an unlocked state. In one or more embodiments, the snubber 104 is coupled to the linkage 124.

[0024] 2 is a schematic diagram of one practical embodiment of a rigid isolator 100. In one or more embodiments, the rigid isolator 100 includes a base 122 and a cap 126. A linkage 124 (FIG. 1) is coupled to the base 122. A cap 126 is coupled to the linkage 124 on an opposite side of the base 122. A snubber 104 is coupled to the base 122 and the cap 126. The snubber 104 is configured to dampen the transmission of vibration between the base 122 and the cap 126 when the linkage 124 is in an unlocked state.

[0025] In one or more embodiments, the linkage 124 ( FIG. 1 ) is configured to transition between an unfixed state in which the cap 126 is movable relative to the base 122 and a fixed state in which the cap 126 is fixed relative to the base 122 in response to changes in temperature. In high energy environments in which the shock and vibration forces applied to the structural system 150 are relatively strong (e.g., having a large magnitude), the rigid isolator 100 uses the linkage 124 in an unfixed state (e.g., one or more joints 102 ( FIG. 1 ) are in a loose fit) to allow movement of the cap 126 relative to the base 122 and uses the dampener 104 to dampen shock and vibration transmitted from the base 122 to the cap 126. In low energy environments in which the shock and vibration forces applied to the structural system 150 are relatively weak (e.g., having a small magnitude), the rigid isolator 100 uses the linkage 124 in a fixed state (e.g., one or more joints 102 are in an interference fit) to securely fasten the base 122 and the cap 126 together.

[0026] In one or more embodiments, the base 122 is configured to be coupled to a first structure 146 (FIG. 3) of a structural system 150 (FIG. 3), and the cap 126 is configured to be coupled to a second structure 148 (FIG. 3) of the structural system 150. In one or more embodiments, the fixed isolator 100 includes at least one interlocking feature 152. The interlocking feature 152 is configured to allow the fixed isolator 100 to be coupled to a structure of the structural system 150. In one embodiment, the base 122 includes at least one interlocking feature 152 and is interlockable with the first structure 146 using the at least one interlocking feature 152. The cap 126 includes at least one interlocking feature 152 and is interlockable with the second structure 148 using the at least one interlocking feature 152.

[0027] In various embodiments, interlocking features 152 may be or take the form of any suitable structure that allows two members to be joined. By way of example, interlocking features 152 may include smooth drilled holes for inserting mechanical fasteners, mating holes for threaded fastener connection, mating surfaces, weldable surfaces, etc. Interlocking features 152 associated with base 122 and interlocking features 152 associated with cap 126 may be the same or different.

[0028] FIG. 3 illustrates, in schematic form, one embodiment of a fixed isolator 100 used to couple together structures of a structural system 150. In one or more embodiments, the structural system 150 includes a first structure 146 and a second structure 148. Although two fixed isolators 100 are shown in FIG. 3 as an example, in other embodiments, any number of fixed isolators 100 can be used to couple together the first structure 146 and the second structure 148. In other embodiments, the structural system 150 can include any number of other structures, which may or may not be coupled together using fixed isolators 100.

[0029] The second structure 148 is coupled to the first structure 146 using the fixed isolators 100. In the embodiment shown, the first structure 146 supports the second structure 148. For example, the first structure 146 is a support structure and the second structure 148 is a part or piece of equipment that is sensitive to shock and vibration. In one embodiment, the structural system 150 forms a portion of an aerospace vehicle, such as a spacecraft or aircraft. The first structure 146 is a component of a frame of the aerospace vehicle and the second structure 148 is a part or piece of equipment of a system of the aerospace vehicle.

[0030] The dampener 104 is configured to dampen vibrations through the structural system 150, such as between the first structure 146 and the second structure 148. In one or more embodiments, the dampener 104 is configured to dampen high frequency vibrations within a range or spectrum of vibration frequencies.

[0031] Thus, in high energy environments where the shock and vibration forces applied to the structural system 150 are relatively strong (e.g., having a large magnitude), the rigid isolators 100 use linkages 124 in a non-fixed state (e.g., one or more joints 102 in a loose fit) to allow movement of the second structure 148 relative to the first structure 146 and use shock absorbers 104 to dampen the shock and vibration transmitted from the first structure 146 to the second structure 148. In low energy environments where the shock and vibration forces applied to the structural system 150 are relatively weak (e.g., having a small magnitude), the rigid isolators 100 use linkages 124 in a fixed state (e.g., one or more joints 102 in an interference fit) to securely fasten the first structure 146 and the second structure 148 together.

[0032] 1, in one or more embodiments, each of one or more joints 102, such as each of the plurality of joints 102, includes a first portion 106 and a second portion 110. The first portion 106 has a first coefficient of thermal expansion ("CTE") 108. The second portion 110 has a second coefficient of thermal expansion 112. The first coefficient of thermal expansion 108 and the second coefficient of thermal expansion 112 are different.

[0033] In one or more embodiments, the coefficient of thermal expansion referred to in relation to the first portion 106 and the second portion 110 of one or more joints 102 refers to the linear coefficient of thermal expansion.

[0034] In one or more embodiments, the difference between the first coefficient of thermal expansion 108 and the second coefficient of thermal expansion 112 is at least approximately 5 (10 -6 In one or more embodiments, the difference between the first coefficient of thermal expansion 108 and the second coefficient of thermal expansion 112 is at least approximately 8 (10 -6 In one or more embodiments, the difference between the first coefficient of thermal expansion 108 and the second coefficient of thermal expansion 112 is at least approximately 14 (10 -6 m / (mK).

[0035] It should be appreciated that a greater difference in the thermal expansion rates of the first portion 106 and the second portion 110 may allow one or more joints 102 to transition between a loose fit state and an interference fit state (e.g., a transition between an unlocked state and a locked state of the linkage 124) in response to a smaller change in temperature (e.g., a smaller ΔT) or at a lower transition temperature. Similarly, a smaller difference in the thermal expansion rates of the first portion 106 and the second portion 110 may allow one or more joints 102 to transition between a loose fit state and an interference fit state (e.g., a transition between an unlocked state and a locked state of the linkage 124) in response to a larger change in temperature (e.g., a larger ΔT) or at a higher transition temperature.

[0036] In one or more embodiments, a first portion 106 of one or more joints 102 is formed from a first material 154 having a first coefficient of thermal expansion 108, and a second portion 110 of the one or more joints 102 is formed from a second material 156 having a second coefficient of thermal expansion 112.

[0037] In one or more embodiments, at least one of the first portion 106 and the second portion 110 of the one or more joints 102 is formed from a metallic material. By way of example, at least one of the first material 154 and the second material 156 may be brass (approximately 19 mm thick). -6 m / (mK)), carbon steel (having a CTE of approximately 11(10 -6 m / (mK)), and tungsten (approximately 4.5(10 -6 m / (mK)) Other metals are also contemplated for the first portion 106 and the second portion 110 of the one or more joints 102.

[0038] In one or more embodiments, at least one of the first portion 106 and the second portion 110 of the one or more joints 102 is formed from a metal alloy. By way of example, at least one of the first material 154 and the second material 156 may be Invar (approximately 1.2(10 -6Nickel-iron alloys such as Inconel (which has a CTE of approximately 11(10 -6 Nickel-chromium alloys such as Cr-Cr-Al-Fe-Nb-O-Pb, which have a CTE of approximately 13.5 (10 -6 In one embodiment, the metal alloy is selected from nickel and copper alloys such as nickel-copper alloys having a CTE of about 0.15 to about 0.25 m / (mK). Other metal alloys are also contemplated for the first portion 106 and the second portion 110 of the one or more joints 102.

[0039] The arrangement of the first portion 106 and the second portion 110 of the one or more joints 102 may depend, for example, on whether the one or more joints 102 are configured to be in a loose fit state at a lower temperature and in an interference fit state at a higher temperature, or alternatively, whether the one or more joints 102 are configured to be in a loose fit state at a higher temperature and in an interference fit state at a lower temperature. The selection of materials for the first portion 106 and the second portion 110 of the one or more joints 102 may depend, for example, on the temperature required to transition the one or more joints 102 between the loose fit state and the interference fit state (referred to herein as the transition temperature (“TT”) 114) and the amount of thermal expansion or contraction achievable at the transition temperature 114.

[0040] In one or more embodiments, one or more joints 102 are configured to be in an interference fit state below the transition temperature 114 and in a loose fit state above the transition temperature 114. For example, the first portion 106 and the second portion 110 are fixed relative to one another below the transition temperature 114 and movable relative to one another above the transition temperature 114. Thus, in these embodiments, the linkage 124 is configured to be in an unfixed state below the transition temperature 114 and in a fixed state above the transition temperature 114.

[0041] In one or more embodiments, one or more joints 102 are configured to be in a loose fit state below the transition temperature 114 and in an interference fit state above the transition temperature 114. For example, the first portion 106 and the second portion 110 are movable relative to one another below the transition temperature 114 and are fixed relative to one another above the transition temperature 114. Thus, in these embodiments, the linkage 124 is in a fixed state below the transition temperature 114 and in an unfixed state above the transition temperature 114.

[0042] 4, in one or more embodiments, linkage 124 includes a first link 128. A first end of first link 128 is coupled to base 122 by a first joint 130. A second end of first link 128 opposite the first end is coupled (e.g., fixed) to cap 126. First joint 130 is one embodiment of one or more of joints 102 (FIG. 1).

[0043] In these examples, the first portion 106 of the first joint 130 is formed by the first end of the first link 128, and the second portion 110 of the first joint 130 is formed by the base 122. In these examples, the first joint 130 allows movement of the first link 128, and therefore movement of the cap 126, relative to the base 122 when the first joint 130 is in a clearance fit, and limits movement of the first link 128, and therefore movement of the cap 126, relative to the base 122 when the first joint 130 is in an interference fit.

[0044] 5 , in one or more embodiments, the linkage 124 includes a first link 128. A first end of the first link 128 is coupled (e.g., fixed) to the base 122. A second end of the first link 128 is coupled to the cap 126 by a first joint 130. The first joint 130 is one embodiment of the one or more joints 102.

[0045] In these examples, the first portion 106 of the first joint 130 is formed by the second end of the first link 128, and the second portion 110 of the first joint 130 is formed by the base 122. In these examples, the first joint 130 allows movement of the cap 126 relative to the first link 128, and therefore movement of the cap 126 relative to the base 122, when the first joint 130 is in a clearance fit, and limits movement of the cap 126 relative to the first link 128, and therefore movement of the cap 126 relative to the base 122, when the first joint 130 is in an interference fit.

[0046] 6, in one or more embodiments, the linkage 124 includes a first link 128 and a second link 132. A first end of the first link 128 is coupled to the base 122 by a first joint 130 of the one or more joints 102. A first end of the second link 132 is coupled to a second end of the first link 128 by a second joint 134 of the one or more joints 102 opposite the base 122. A second end of the second link 132 is coupled to the cap 126 by a third joint 136 of the one or more joints 102 opposite the first link 128. The second joint 134 is one embodiment of one of the one or more joints 102 (FIG. 1). The third joint 136 is one embodiment of one of the one or more joints 102.

[0047] In these embodiments, a first portion 106 of the first joint 130 is formed by a first end of the first link 128, and a second portion 110 of the first joint 130 is formed by the base 122. A first portion 106 of the second joint 134 is formed by a second end of the first link 128, and a second portion 110 of the second joint 134 is formed by a first end of the second link 132. A first portion 106 of the third joint 136 is formed by a second end of the second link 132, and a second portion 110 of the third joint 136 is formed by the cap 126.

[0048] In these illustrative examples, the first joint 130 allows movement of the first link 128, and therefore the cap 126, relative to the base 122 when the first joint 130 is in a clearance fit state, and limits movement of the first link 128, and therefore the cap 126, relative to the base 122 when the first joint 130 is in an interference fit state. The second joint 134 allows movement of the second link 132, and therefore the cap 126, relative to the base 122 when the second joint 134 is in a clearance fit state, and limits movement of the second link 132, and therefore the cap 126, relative to the base 122 when the second joint 134 is in an interference fit state. The third joint 136 allows movement of the cap 126 relative to the second link 132, and therefore movement of the cap 126 relative to the base 122, when the third joint 136 is in a clearance fit state, and limits movement of the cap 126 relative to the second link 132, and therefore movement of the cap 126 relative to the base 122, when the third joint 136 is in an interference fit state.

[0049] Although FIG. 6 illustrates one embodiment of a fixed isolator 100 in which the linkage 124 has two links (e.g., a first link 128 and a second link 132) and three joints 102 (e.g., a first joint 130, a second joint 134, and a third joint 136) connecting the linkage 124, the base 122, and the cap 126 together, in other embodiments, the fixed isolator 100 may include other configurations of linkages 124, any number of links, and any number of joints 102.

[0050] In various embodiments, each joint 102 of the one or more joints 102, such as first joint 130, second joint 134, and third joint 136, is configured to transition between the loose fit state and the interference fit state at a transition temperature 114 ( FIG. 1 ). In one or more embodiments, the transition temperature 114 for each joint 102 of the one or more joints 102, such as each of the multiple joints 102, is the same. In one or more other embodiments, the transition temperature 114 for at least one of the plurality of joints 102 is different from the transition temperature 114 for at least another one of the plurality of joints 102. In one or more other embodiments, the transition temperature 114 for each joint 102 of the one or more joints 102, such as each of the plurality of joints 102, is different. Thus, depending on the number of joints 102, the types of joints 102, and the configuration and arrangement of the joints 102, the fixed isolator 100 can control the amount and / or type of movement through the linkage 124 at one or more different transition temperatures 114.

[0051] Still referring to FIG. 6, in one or more embodiments, a first transition temperature ("T T1 Above a first transition temperature ("T") 138, the first joint 130 has a clearance fit at which the first link 128 is movable relative to the base 122. In one or more embodiments, a first transition temperature ("T T1 Above the base 122 , the first joint 130 has a fixed interference fit with the first link 128 relative to the base 122 .

[0052] In one or more embodiments, the second transition temperature ("T T2 Above a second transition temperature ("T") 140, the second joint 134 has a clearance fit where the second link 132 is movable relative to the first link 128. In one or more embodiments, a second transition temperature ("T T2 Above the first link 128 , the second joint 134 has a fixed interference fit with the second link 132 relative to the first link 128 .

[0053] In one or more embodiments, a third transition temperature ("TT3 Above a third transition temperature ("T") 142, the third joint 136 has a clearance fit that allows the cap 126 to move relative to the second link 132. In one or more embodiments, a third transition temperature ("T T3 Above the cap 126 and the second link 132, the third joint 136 has an interference fit with the cap 126 secured to the second link 132.

[0054] In one or more embodiments, the first transition temperature 138, the second transition temperature 140, and the third transition temperature 142 are the same. In one or more embodiments, at least one of the first transition temperature 138, the second transition temperature 140, and the third transition temperature 142 is different from at least another one of the first transition temperature 138, the second transition temperature 140, and the third transition temperature 142. In one or more embodiments, each of the first transition temperature 138, the second transition temperature 140, and the third transition temperature 142 are different.

[0055] 5 and 6, in one or more embodiments, at least one of the one or more joints 102, such as at least one of the plurality of joints 102, is configured to move linearly when in a clearance fit. In one or more embodiments, at least one of the one or more joints 102, such as the first joint 130 of FIG. 5 or the second joint 134 of FIG. 6, includes or takes the form of a slide bearing, a plain bearing, a linear sliding joint, a prismatic joint, or the like.

[0056] 4 and 6, in one or more embodiments, at least one of the one or more joints 102, such as at least one of the plurality of joints 102, is configured to pivot or rotate when in a clearance fit. In one or more embodiments, at least one of the one or more joints 102, such as the first joint 130 of FIGS. 4 and 6 or the third joint 136 of FIG. 6, includes or takes the form of a spherical bearing, a rotary joint, a ball joint, or the like.

[0057] In one or more embodiments, the stationary isolator 100 is configured to allow linear movement between the cap 126 and the base 122, and thus linear movement between the second structure 148 and the first structure 146 (FIG. 3). In these embodiments, such as shown in FIG. 5, one or more of the joints 102 (e.g., the first joint 130) include a plain bearing.

[0058] In one or more embodiments, the stationary isolator 100 is configured to allow pivotal or rotational movement between the cap 126 and the base 122, and thus between the second structure 148 and the first structure 146 (FIG. 3). In these embodiments, such as shown in FIG. 4, one or more of the joints 102 (e.g., the first joint 130) include a spherical bearing.

[0059] In one or more embodiments, the stationary isolator 100 is configured to allow both linear and pivotal or rotational movement between the cap 126 and the base 122, and thus both linear and pivotal or rotational movement between the second structure 148 and the first structure 146 (FIG. 3). In these embodiments, such as those shown in FIG. 6, at least one of the one or more joints 102 (e.g., the first joint 130 and the third joint 136) includes a spherical bearing and at least one of the one or more joints 102 (e.g., the second joint 134) includes a plain bearing.

[0060] 4-6, in one or more embodiments, the bumper 104 includes or takes the form of an elastomeric member 158 (e.g., formed from an elastomeric material). In one or more embodiments, the bumper 104, such as the elastomeric member 158, is disposed about (e.g., surrounds) the linkage 124 and forms a housing 144 (e.g., the outer housing of the stationary isolator 100) that extends between the base 122 and the cap 126.

[0061] In one or more embodiments, the elastomeric member 158 is formed from natural rubber. In one or more embodiments, the elastomeric member 158 is formed from synthetic rubber. In one or more embodiments, the elastomeric member 158 is formed from isoprene. In one or more embodiments, the elastomeric member 158 is formed from silicone. In one or more embodiments, the elastomeric member 158 is formed from at least one of natural rubber, synthetic rubber, isoprene, silicone, polyisoprene, butadiene styrene (e.g., styrene butadiene rubber (SBR)), polychloroprene (e.g., polychloroprene rubber), ethylene propylene diene monomer (EPDM) rubber, polyacrylic acid, and polyurethane.

[0062] 7, in one or more embodiments, the snubber 104 includes or takes the form of a spring 160. In one or more embodiments, the snubber 104, such as the spring 160, is a coil spring that is disposed about the linkage 124 and extends between the base 122 and the cap 126. In certain applications, such as the aerospace industry, it may be beneficial to use the spring 160 as the snubber 104 instead of the elastomeric member 158, as the spring 160 is less susceptible to outgassing.

[0063] In other embodiments, other types of shock and vibration absorbing members and / or materials are used as bumper 104. As one example, bumper 104 may include at least one shock and vibration absorbing member coupled to and extending between base 122 and cap 126 without forming an outer housing of stationary isolator 100. In such embodiments, the shock and vibration absorbing member is expandable, compressible, and flexible.

[0064] 8, in one or more embodiments, the stationary isolator 100 includes a heating element 116. The heating element 116 is configured to effect a change in temperature. For example, the heating element 116 is configured to increase a temperature of at least one of the one or more joints 102, such as at least one of the plurality of joints 102, above a transition temperature 114 (FIG. 1) of the one or more joints 102 to transition the one or more joints 102 between a loose fit state and an interference fit state.

[0065] In one or more embodiments, the heating element 116 is in thermal communication with the linkage 124. In one or more embodiments, the heating element 116 is in thermal communication with one or more joints 102, such as at least one or each of the plurality of joints 102. In these embodiments, a single heating element 116 is used to heat one or more joints 102, such as each of the plurality of joints 102, such as the first joint 130, the second joint 134, and the third joint 136 shown in FIG.

[0066] In one or more embodiments, the stationary isolator 100 includes a plurality of heating elements 116. In these embodiments, each of the plurality of heating elements 116 is configured to heat a corresponding joint 102 of the one or more joints 102, such as a corresponding one of the plurality of joints 102. For example, an independent heating element 116 is used to heat each joint 102 of the one or more joints 102, such as each of the plurality of joints 102, such as the first joint 130, the second joint 134, and the third joint 136 shown in FIG.

[0067] 8, a first one or more of the heating elements 116 are configured to heat the first joint 130 above a first transition temperature 138 to transition the first joint 130 from a loose fit state to an interference fit state, or to transition the first joint 130 from an interference fit state to a loose fit state. A second one or more of the heating elements 116 are configured to heat the second joint 134 above a second transition temperature 140 to transition the first joint 130 from a loose fit state to an interference fit state, or to transition the first joint 130 from an interference fit state to a loose fit state. The third one or more of the heating elements 116 are configured to heat the third joint 136 above a third transition temperature 142 to transition the third joint 136 from a clearance fit state to an interference fit state or to transition the third joint 136 from an interference fit state to a clearance fit state.

[0068] In one or more embodiments, the heating element 116 includes or takes the form of at least one coil heater, such as a high resistance heating element. In one or more embodiments, the heating element 116 (e.g., a coil heater) is coupled to (e.g., wrapped around) at least a portion of at least one of the linkage 124, the one or more joints 102, the base 122, and / or the cap 126. In one or more embodiments, the heating element 116 includes a nichrome heating element covered by a silicone or ceramic insulation layer.

[0069] In one or more embodiments, the heating element 116 includes or takes the form of a thermoelectric heater. In other embodiments, various other suitable types of heaters or heating devices are contemplated for use with heating element 116.

[0070] 9, in one or more embodiments, the stationary isolator 100 includes a cooling element 162. The cooling element 162 is configured to effect a change in temperature. For example, the cooling element 162 is configured to reduce a temperature of at least one of the one or more joints 102, such as at least one of the plurality of joints 102, below a transition temperature 114 ( FIG. 1 ) of the one or more joints 102 to transition the one or more joints 102 between a clearance fit state and an interference fit state.

[0071] In one or more embodiments, a cooling element 162 is in thermal communication with the linkage 124. In one or more embodiments, a cooling element 162 is in thermal communication with one or more joints 102, such as at least one or each of the plurality of joints 102. In these embodiments, a single cooling element 162 is used to remove heat (e.g., cool) from each joint 102 of the one or more joints 102, such as each of the plurality of joints 102, such as the first joint 130, the second joint 134, and the third joint 136 shown in FIG.

[0072] In one or more embodiments, the stationary isolator 100 includes a plurality of cooling elements 162. In these embodiments, each of the plurality of cooling elements 162 is configured to remove heat (e.g., cool) from a corresponding joint 102 of the one or more joints 102, such as a corresponding one of the plurality of joints 102. For example, an independent cooling element 162 may be used to remove heat from each joint 102 of the one or more joints 102, such as each of the plurality of joints 102, such as the first joint 130, the second joint 134, and the third joint 136 shown in FIG.

[0073] 9, a first one or more of the cooling elements 162 are configured to cool the first joint 130 below a first transition temperature 138 to transition the first joint 130 from a loose fit state to an interference fit state or transition the first joint 130 from an interference fit state to a loose fit state. A second one or more of the cooling elements 162 are configured to cool the second joint 134 below a second transition temperature 140 to transition the first joint 130 from a loose fit state to an interference fit state or transition the first joint 130 from an interference fit state to a loose fit state. The third one or more of the cooling elements 162 are configured to cool the third joint 136 below the third transition temperature 142 to transition the third joint 136 from a clearance fit state to an interference fit state or to transition the third joint 136 from an interference fit state to a clearance fit state.

[0074] In one or more embodiments, the cooling element 162 includes or takes the form of at least one thermoelectric element, such as a Peltier element. In one or more embodiments, the cooling element 162 also includes a heat sink (e.g., a radiator plate, a finned heat sink, etc.).

[0075] In one or more embodiments, the stationary isolator 100 includes a combination of at least one heating element 116 ( FIG. 8 ) and at least one cooling element 162. In these embodiments, the heating element 116 is configured to heat at least one of the one or more joints 102, such as at least one of the plurality of joints 102, above the transition temperature 114 ( FIG. 1 ), and the cooling element 162 is configured to cool at least one of the one or more joints 102, such as at least one of the plurality of joints 102, below the transition temperature 114.

[0076] 1 , in one or more embodiments, heating element 116 and / or cooling element 162 are powered by an external power source 164, which in one or more embodiments is a source of power provided by structural system 150 (e.g., an aerospace vehicle) or any other suitable external source. In one or more embodiments, external power source 164 is a battery 174 or other power storage cell.

[0077] In one or more embodiments, the heating element 116 and / or the cooling element 162 are powered by an internal power source 166. For example, the internal power source 166 forms part of the stationary isolator 100. In one or more embodiments, the internal power source 166 includes a suitable generator configured to generate power in response to vibrations (e.g., convert vibrational power into electrical energy).

[0078] 8 and 9, in one or more embodiments, stationary isolator 100 includes a piezoelectric generator 118. Piezoelectric generator 118 is one embodiment of internal power source 166 (FIG. 1). Piezoelectric generator 118 is configured to generate electrical power in response to mechanical strain.

[0079] As shown in Figure 8, in one or more embodiments, a piezoelectric generator 118 is in electrical communication with the heating element 116. Electrical power drives a current through the heating element 116. As shown in Figure 9, in one or more embodiments, a piezoelectric generator 118 is in electrical communication with the cooling element 162. Electrical power drives a current through the cooling element 162.

[0080] In one or more embodiments, a piezoelectric generator 118 is in electrical communication with the plurality of heating elements 116. Electrical power drives current through each of the plurality of heating elements 116. In one or more embodiments, a piezoelectric generator 118 is in electrical communication with the plurality of cooling elements 162. Electrical power drives current through each of the plurality of cooling elements 162.

[0081] 8-10, in one or more embodiments, the piezoelectric generator 118 includes a piezoelectric cantilever 120. In one or more embodiments, the piezoelectric generator 118 includes a plurality of piezoelectric cantilevers 120 (FIGS. 8 and 9). The piezoelectric cantilevers 120, such as each of the plurality of piezoelectric cantilevers 120, are configured to bend in response to vibration.

[0082] 10, in one or more embodiments, a piezoelectric cantilever 120, such as each of the plurality of piezoelectric cantilevers 120 (FIGS. 8 and 9), has a length L. In one or more embodiments, the length L is selected to resonate at an approximate frequency of vibration or a range of approximate frequencies of vibration. For example, the length L is lengthened or shortened to tune (e.g., modify or selectively tune) the piezoelectric cantilever 120 to a selected or desired resonant frequency or range of resonant frequencies.

[0083] In one embodiment, the length L is selected to resonate between approximately 40 Hz and approximately 5,000 Hz. In another embodiment, the length L is selected to resonate between approximately 60 Hz and approximately 1,200 Hz. In yet another embodiment, the length L is selected to resonate between approximately 100 Hz and approximately 300 Hz.

[0084] In one or more embodiments, the piezoelectric cantilever 120 includes at least one piezoelectric element 168, such as a strip of piezoelectric material. In one or more embodiments, the piezoelectric cantilever 120 includes at least one support element 170, such as a strip of support material. In these embodiments, the at least one piezoelectric element 168 is coupled to and supported by the at least one support element 170. In one or more embodiments, the piezoelectric cantilever 120 is a laminate structure formed by at least one layer of the piezoelectric element 168 coupled to and supported by at least one layer of the support element 170.

[0085] In these embodiments, the use of support element 170 depends on, for example, the magnitude of shock and vibration forces acting on piezoelectric cantilever 120 during a high energy event. For example, support element 170 is used to provide support to piezoelectric element 168 when piezoelectric cantilever 120 is intended for use in very high energy environments where shock and vibration forces are relatively strong.

[0086] In one or more embodiments, the piezoelectric cantilever 120 is a laminate structure formed by multiple layers of piezoelectric elements 168. The additional layers of piezoelectric elements 168 provide additional electrical current in response to mechanical strain induced in the piezoelectric cantilever 120 in response to bending of the piezoelectric cantilever 120 due to shock and vibration.

[0087] In one exemplary embodiment, the support element 170 of a piezoelectric cantilever 120, such as each of the plurality of piezoelectric cantilevers 120 (FIGS. 8 and 9), is made of aluminum and has a thickness of approximately 0.032 inches (0.81 millimeters). In one implementation of this embodiment, the length L of a piezoelectric cantilever 120, such as the support element 170 of a piezoelectric cantilever 120, is approximately 0.5 inches (12.7 millimeters) and resonates at approximately 4,064 Hz. In another implementation of this embodiment, the length L of a piezoelectric cantilever 120, such as the support element 170 of a piezoelectric cantilever 120, is approximately 1.0 inches (25.4 millimeters) and resonates at approximately 1,016 Hz. In another implementation of this embodiment, the length L of a piezoelectric cantilever 120, such as the support element 170 of a piezoelectric cantilever 120, is approximately 2.0 inches (50.8 millimeters) and resonates at approximately 254 Hz. In one example of this embodiment, the length L of a piezoelectric cantilever 120, such as support element 170 of piezoelectric cantilever 120, is approximately 3.0 inches (76.2 millimeters) and resonates at approximately 113 Hz. In another example of this embodiment, the length L of a piezoelectric cantilever 120, such as support element 170 of piezoelectric cantilever 120, is approximately 4.0 inches (101.6 millimeters) and resonates at approximately 64 Hz. In yet another example of this embodiment, the length L of a piezoelectric cantilever 120, such as support element 170 of piezoelectric cantilever 120, is approximately 5.0 inches (127 millimeters) and resonates at approximately 41 Hz.

[0088] In one or more embodiments, the piezoelectric cantilever 120, such as the support element 170 of the piezoelectric cantilever 120, has any one of a variety of thicknesses. For example, the thickness of the piezoelectric cantilever 120, such as the thickness of the support element 170 of the piezoelectric cantilever 120, can be made thicker or thinner to tune (e.g., modify or selectively tune) the resonant frequency of the piezoelectric cantilever 120 to a selected or desired resonant frequency, or to tune the length L of the piezoelectric cantilever 120 to a selected or desired resonant frequency.

[0089] In one or more embodiments, the support element 170 and the piezoelectric element 168 have the same length (e.g., length L), as shown in Figure 10. In one or more other embodiments, the support element 170 and the piezoelectric element 168 have different lengths. For example, the support element 170 forms the length L of the piezoelectric cantilever 120, and the piezoelectric element 168 is attached to the support element 170 and has a length that is less than the length of the support element 170.

[0090] 11, various other configurations of the piezoelectric generator 118 are contemplated in one or more embodiments. In one or more embodiments, at least one piezoelectric element 168 is coupled to the bumper 104. In these embodiments, deformation of the bumper 104 due to shock and vibration causes the piezoelectric element 168 to deform (e.g., compress, bend, etc.) and thus induce mechanical strain in the piezoelectric element 168. In one or more embodiments, at least one piezoelectric element 168 is coupled between the base 122 and the cap 126. In these embodiments, movement of the cap 126 relative to the base 122 due to shock and vibration causes the piezoelectric element 168 to deform (e.g., compress, bend, etc.) and thus induce mechanical strain in the piezoelectric element 168. In one or more embodiments, the piezoelectric generator 118 includes combinations of various configurations of the piezoelectric element 168, such as taking the form of a piezoelectric cantilever 120, being coupled to the bumper 104, and / or being coupled between the base 122 and the cap 126.

[0091] Thus, in embodiments of the rigid isolators 100 that utilize an internal power source 166, such as a piezoelectric generator 118, the power needed to heat and / or cool one or more joints 102 is provided passively in response to shock and vibration forces acting on the rigid isolators 100. Such passive power generation is not dependent on computer control or external power, beneficially reducing the likelihood of failure.

[0092] 1 , in one or more embodiments, an internal power source 166, such as a piezoelectric generator 118, is coupled to and in electrical communication with an external power source 164, such as a battery 174. In these embodiments, the electrical energy generated by the piezoelectric generator 118 is not immediately used to drive electrical current through the heating element 116 and / or the cooling element 162, but is instead transferred to and stored in the battery 174 for later use. In these embodiments, the electrical energy stored in the battery 174 is selectively provided to the heating element 116 and / or the cooling element 162 by a controller 172, such as at a desired time or for a desired period of time.

[0093] 12, by way of example, the present disclosure is also directed to a method 1000 of isolating a first structure from a second structure. For example, method 1000 may relate to isolating a first structure 146 of a structural system 150 from a second structure 148 of the structural system 150. Referring generally to FIGS. 1-11, in one or more embodiments, an implementation of method 1000 is performed using a stationary isolator 100 of the present disclosure.

[0094] The method 1000 includes coupling structures together (block 1002) using fixed isolators 100. In one or more embodiments, coupling structures together (block 1002) includes coupling a first structure 146 of a structural system 150 and a second structure 148 of the structural system 150 together using fixed isolators 100.

[0095] In one or more embodiments, the step of coupling the structures together (block 1002) includes coupling together a first structure 146 of the structural system 150 and a second structure 148 of the structural system 150 using a plurality of fixed isolators 100.

[0096] The method 1000 further includes transitioning the stationary isolator 100 between the loose fit state and the interference fit state in response to changes in temperature (block 1004).

[0097] In one or more embodiments, the step of transitioning the fixed isolator 100 between a clearance fit state and an interference fit state (block 1004) includes transitioning one or more joints 102 of the fixed isolator 100 between a clearance fit state in which the first structure 146 and the second structure 148 are movable relative to one another, and an interference fit state in which the first structure 146 and the second structure 148 are fixed relative to one another in response to a change in temperature.

[0098] In one or more embodiments, the step of transitioning the fixed isolator 100 between a clearance fit state and an interference fit state (block 1004) includes transitioning one or more joints 102, such as multiple joints 102 of the fixed isolator 100, between a clearance fit state in which the first structure 146 and the second structure 148 are movable relative to each other, and an interference fit state in which the first structure 146 and the second structure 148 are fixed relative to each other in response to a change in temperature.

[0099] In one or more embodiments, the step of transitioning the fixed isolator 100 between the clearance fit state and the interference fit state (block 1004) includes transitioning the linkage 124 of the fixed isolator 100 between an unfixed state in which the first structure 146 and the second structure 148 are movable relative to each other, and a fixed state in which the first structure 146 and the second structure 148 are fixed relative to each other in response to a change in temperature.

[0100] In one or more embodiments, the method 1000 includes isolating the structures (block 1006). In one or more embodiments, isolating the structures (block 1006) includes isolating the second structure 148 from the first structure 146 by configuring one or more joints 102, such as at least one of the plurality of joints 102, in a loose fit or by configuring the linkage 124 in an unlocked state, thereby allowing the second structure 148 to move relative to the first structure 146.

[0101] In one or more embodiments, the method 1000 includes securing the structures (block 1008). In one or more embodiments, securing the structures (block 1008) includes securing the first structure 146 and the second structure 148 together by configuring one or more joints 102, such as each of the plurality of joints 102, in an interference fit or by configuring the linkage 124 in a fixed state.

[0102] The method 1000 further includes attenuating (block 1010) the transmission of vibration between the structures using the fixed isolators 100. In one or more embodiments, attenuating (block 1010) the transmission of vibration includes attenuating the transmission of vibration between the first structure 146 and the second structure 148 using the dampers 104 of the fixed isolators 100 when one or more joints 102, such as at least one or each of the plurality of joints 102, are in a clearance fit.

[0103] In one or more embodiments, the step of damping the transmission of vibration (block 1010) includes using the shock absorber 104 of the fixed isolator 100 to damp the transmission of vibration between the first structure 146 and the second structure 148 with the linkage 124 unfixed.

[0104] In one or more embodiments, the method 1000 includes heating (block 1012) the fixed isolator 100. In these embodiments, heating the fixed isolator 100 effects or causes a change in temperature, such as above the transition temperature 114, of one or more joints 102.

[0105] In one or more embodiments, the step of heating the stationary isolator 100 (block 1012) includes moving the structural system 150 from a first ambient temperature to a second ambient temperature, where the second ambient temperature is higher than the first ambient temperature and higher than the transition temperature 114.

[0106] In one or more embodiments, heating the stationary isolator 100 (block 1012) includes heating one or more joints 102, such as at least one of the plurality of joints 102, to a temperature above the transition temperature 114. In one or more embodiments, heating the stationary isolator 100 (block 1012) includes heating one or more joints 102, such as at least one of the plurality of joints 102, using a heating element 116.

[0107] In one or more embodiments, the method 1000 includes cooling (block 1014) the stationary isolator 100. In these embodiments, cooling the stationary isolator 100 effects or causes a change in temperature, such as to below the transition temperature 114, of one or more joints 102.

[0108] In one or more embodiments, the step of cooling the stationary isolator 100 (block 1014) includes moving the structural system 150 from a first ambient temperature to a second ambient temperature, where the second ambient temperature is less than the first ambient temperature and less than the transition temperature 114.

[0109] In one or more embodiments, cooling the stationary isolator 100 (block 1014) includes cooling (e.g., removing heat from) one or more joints 102, such as at least one of the plurality of joints 102, to a temperature below the transition temperature 114. In one or more embodiments, cooling the stationary isolator 100 (block 1014) includes cooling one or more joints 102, such as at least one of the plurality of joints 102, using a cooling element 162.

[0110] In one or more embodiments, each of one or more joints 102, such as each of the plurality of joints 102, includes a first portion 106 having a first coefficient of thermal expansion 108 and a second portion 110 having a second coefficient of thermal expansion 112. The first coefficient of thermal expansion 108 and the second coefficient of thermal expansion 112 are different.

[0111] In one or more embodiments, the step of heating the fixed isolator 100 (block 1012) includes heating one or more joints 102, such as at least one of the multiple joints 102, above a transition temperature 114 to cause the first portion 106 to expand relative to the second portion 110 or the second portion 110 to expand relative to the first portion 106.

[0112] In one or more embodiments, the step of cooling the fixed isolator 100 (block 1014) includes cooling one or more joints 102, such as at least one of the multiple joints 102, to below a transition temperature 114 to cause the first portion 106 to contract relative to the second portion 110 or the second portion 110 to contract relative to the first portion 106.

[0113] In one or more embodiments, heating the stationary isolator 100 (block 1012) includes generating electrical power in response to mechanical strain using a piezoelectric generator 118 and using the electrical power to pass an electrical current through the heating element 116.

[0114] In one or more embodiments, cooling the stationary isolator 100 (block 1014) includes using a piezoelectric generator 118 to generate electrical power in response to mechanical strain and using the electrical power to pass an electrical current through the cooling element 162.

[0115] In one or more embodiments, the piezoelectric generator 118 includes a piezoelectric cantilever 120, such as a plurality of piezoelectric cantilevers 120. In these embodiments, generating electrical power includes bending a piezoelectric cantilever 120, such as at least one or each of the plurality of piezoelectric cantilevers 120, in response to a vibration. The bending of the piezoelectric cantilever 120, such as one or more of the plurality of piezoelectric cantilevers 120, generates a mechanical strain.

[0116] In one or more embodiments, bending a piezoelectric cantilever 120, such as one or more of the plurality of piezoelectric cantilevers 120, includes resonating a piezoelectric cantilever 120, such as at least one or each of the plurality of piezoelectric cantilevers 120, in a range of vibration frequencies.

[0117] Thus, the rigid isolators 100 and methods 1000 of the present disclosure provide selective isolation of vibration between structures in certain environments, such as between a support structure and a piece of equipment that is sensitive to shock and vibration in a high energy dynamic environment. The rigid isolators 100 and methods 1000 of the present disclosure also provide selective isolation between structures in certain other environments, such as between a support structure and a piece of equipment in a low energy or substantially static environment.

[0118] The rigid isolators 100 and methods 1000 of the present disclosure advantageously allow numerous tuning options for thermal activation and deactivation and / or vibration activation and deactivation. As an example, the rigid isolators 100 can be tuned to provide stiffness at lower vibration levels (e.g., smaller magnitude) and flexibility (with shock and vibration absorption) at higher vibration levels (e.g., larger magnitude). As another example, the rigid isolators 100 can be tuned to provide flexibility (with shock and vibration absorption) at lower vibration levels (e.g., smaller magnitude) and stiffness at higher vibration levels (e.g., larger magnitude). As another example, the rigid isolators 100 can be tuned to provide stiffness at lower temperatures and flexibility (with shock and vibration absorption) at higher temperatures. As another example, the rigid isolators 100 can be tuned to provide flexibility (with shock and vibration absorption) at lower temperatures and stiffness at higher temperatures.

[0119] In some implementations of the presently disclosed rigid isolators 100 and methods 1000, the selection between the isolated and rigid states is performed passively. In other words, in one or more implementations, the presently disclosed rigid isolators 100 and methods 1000 advantageously do not require external power or external control. For example, the selection between the isolated and rigid states occurs due to a change in the environment. As one example, the selection between the isolated and rigid states occurs in response to a change in temperature of the surrounding environment, such as when the ambient temperature exceeds a threshold temperature. As another example, the selection between the isolated and rigid states occurs in response to a change in vibration, such as when the vibration (e.g., the magnitude of the vibration) exceeds a threshold vibration level (e.g., a threshold magnitude of vibration). In these implementations, a magnitude of vibration above a preselected threshold generates sufficient power using the piezoelectric generator 118 to heat or cool one or more joints 102 using the heating element 116 or cooling element 162, respectively, to cause a transition between the isolated and rigid states.

[0120] In some embodiments of the presently disclosed stationary isolator 100 and method 1000, the selection between the isolated state and the stationary state is actively performed. In these embodiments, electrical energy is provided by an external power source 164, such as a battery 174, at predetermined selected times.

[0121] 13 and 14, embodiments of the stationary isolator 100 and method 1000 may be used in the context of an aerospace vehicle manufacturing and service method 1100 as shown in the flow diagram of FIG. 13, and an aerospace vehicle 1200 as shown generally in FIG. 14.

[0122] 14 , aerospace vehicle 1200 may include any one of a variety of types of vehicles capable of traveling within and outside of the Earth's atmosphere, such as, but not limited to, aircraft, spacecraft, satellites, rockets, etc. In one or more embodiments, aerospace vehicle 1200 includes an underlying frame 1202, an interior 1206, and a number of high level systems 1204. Examples of high level systems 1204 include one or more of a propulsion system 1208, an electrical system 1210, a hydraulic system 1212, an environmental system 1214, a communication system 1216, a guidance system 1218, and a vision system 1220. In other embodiments, aerospace vehicle 1200 may include any number of other types of systems 1222.

[0123] Using embodiments of the stationary isolator 100 and implementations of the method 1000, a portion or piece of equipment associated with one of the high level systems 1204 that is sensitive to shock and vibration forces can be coupled to the frame 1202. Thus, the equipment or piece may be rigidly fixed in certain environments and isolated in other environments.

[0124] 13, during pre-production, the method 1100 includes specification and design (block 1102) of the aerospace vehicle 1200 and procurement of materials (block 1104). During production of the aerospace vehicle 1200, components and subassemblies of the aerospace vehicle 1200 are manufactured (block 1106) and system integrated (block 1108). The aerospace vehicle 1200 then undergoes certification and delivery (block 1110) and is placed into service (block 1112). Routine maintenance and service (block 1114) includes modification, reconfiguration, refurbishment, etc. of one or more systems of the aerospace vehicle 1200.

[0125] Each of the processes of method 1100 shown in Figure 13 may be performed or carried out by a system integrator, a third party, and / or an operator (e.g., a customer). For purposes of this specification, a system integrator may include, but is not limited to, any number of manufacturers and major system subcontractors, a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers, and an operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0126] The illustrated and described herein embodiments of the static isolators 100 and methods 1000 may be employed during any one or more of the stages of the manufacturing and service method 1100 depicted in the flow diagram illustrated by FIG. 13. In one embodiment, the disclosed embodiments of the static isolators 100 and methods 1000 may form part of the component and subassembly manufacturing (block 1106) and / or system integration (block 1108). For example, the assembly of the aerospace vehicle 1200 and / or the installation of its various equipment and components using the disclosed embodiments of the static isolators 100 and methods 1000 may correspond to the component and subassembly manufacturing (block 1106) and may be prepared in a similar manner to the components or subassemblies that are prepared while the aerospace vehicle 1200 is in service (block 1112). Additionally, embodiments of the presently disclosed stationary isolators 100 and methods 1000 may be utilized during system integration (block 1108) and certification and delivery (block 1110). Similarly, embodiments of the presently disclosed stationary isolators 100 and methods 1000 may be utilized, for example, but not limited to, while the aerospace vehicle 1200 is in service (block 1112) and during maintenance and upkeep (block 1114).

[0127] Although an aerospace (e.g., aircraft or spacecraft) example is shown, the embodiments and principles disclosed herein also apply to the automotive, construction, electrical, wind turbine, and other design and manufacturing industries, etc. Thus, in addition to aircraft and spacecraft, the embodiments and principles disclosed herein may also be applied to other vehicles (such as land vehicles, marine vehicles, construction vehicles, etc.), machinery, and independent structures.

[0128] As used herein, a system, apparatus, device, structure, article, element, component, or hardware that is "configured to" perform a particular function is not in fact capable of performing the particular function without any modification, but rather may perform the particular function after further modification. In other words, a system, apparatus, device, structure, article, element, component, or hardware that is "configured to" perform a particular function is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing the particular function. As used herein, the phrase "configured to" refers to existing characteristics of a system, apparatus, structure, article, element, component, or hardware that enable the system, apparatus, structure, article, element, component, or hardware to perform a particular function without further modification. For purposes of this disclosure, a system, apparatus, device, structure, article, element, component, or hardware that is described as being "configured" to perform a particular function may additionally or alternatively be described as being "adapted to" and / or "operative to" perform that function.

[0129] Unless otherwise stated, the terms "first," "second," "third," etc. are used herein merely as labels and are not intended to impose any sequential, positional, or hierarchical requirements on the items they refer to. Further, reference to, for example, a "second" item does not require or exclude, for example, a "first" or smaller number item, and / or a "third" or larger number item.

[0130] For purposes of this disclosure, "coupled," "coupling," and similar terms and phrases refer to two or more elements that are joined, coupled, fastened, attached, connected, in communication, or otherwise associated with one another (e.g., mechanically, electrically, fluidly, optically, electromagnetically). In various embodiments, these elements may be directly or indirectly coupled. As one example, element A may be directly coupled to element B. As another example, element A may be indirectly coupled to element B, for example, via another element C.

[0131] As used herein, the terms "about" and "approximately" refer to conditions that are close to, but not exactly, the stated condition that still performs a desired function or achieves a desired result. By way of example, the terms "about" and "approximately" refer to conditions that are within a given acceptable tolerance or precision. By way of example, the terms "about" and "approximately" refer to conditions that are within 10% of the stated condition. However, the terms "about" and "approximately" do not exclude conditions that are exactly the stated condition.

[0132] In the above-referenced Figures 1 and 14, blocks represent functional elements, features, and / or components related to embodiments of the subject matter disclosed herein. If any, the lines connecting the various elements, features, and / or components represent their mechanical, electrical, fluid, optical, electromagnetic, and other connections and / or combinations. If any, the elements, features, and components represented by dashed lines may be provided in an alternative or represent alternative examples of the subject matter disclosed herein. If any, the dashed lines connecting blocks designating the various elements, features, and / or components represent connections similar in function and purpose to those represented by solid lines. However, the connections represented by dashed lines may be provided in an alternative or relate to alternative examples of the subject matter disclosed herein. If any, environmental elements are represented by dotted lines. It should be understood that not all connections between the various disclosed elements, features, and / or components are necessarily represented. Thus, there may be connections other than those shown in the drawings.

[0133] In the above-mentioned FIGS. 1-11 and 14, phantom (imaginary) elements may be shown for clarity. Those skilled in the art will appreciate that some of the elements, features, and / or components shown in FIGS. 1-11 and 14 may be combined in various ways (even if such one or more combinations are not expressly stated herein) without necessarily including other features described and illustrated in FIGS. 1-11 and 14, other drawings, and / or the accompanying disclosure. Similarly, additional features not limited to the examples presented may be combined with some or all of the features shown and described herein. Unless expressly stated otherwise, the schematic diagrams of the examples depicted in the above-mentioned FIGS. 1-11 and 14 are not intended to imply architectural limitations with respect to the example embodiments. Rather, although certain example structures are shown, it should be understood that the structures may be modified, where appropriate. Thus, modifications, additions, and / or omissions may be made to the illustrated structures. Further, those skilled in the art will appreciate that not all elements described and shown in Figures 1-11 and 14 referenced above need to be included in every embodiment, and not all elements described herein necessarily will be present in every illustrative embodiment.

[0134] In the above-mentioned Figures 12 and 13, the blocks may represent operations, steps, and / or portions thereof, and the lines connecting the various blocks do not imply any particular order or dependency of the operations or portions thereof. The blocks shown with dashed lines represent alternative operations and / or portions thereof. It will be understood that not all dependencies between the various operations disclosed are necessarily represented. Figures 12 and 13, which describe the operations of the disclosed method presented herein, and the accompanying disclosure, should not be construed as necessarily dictating the order in which the operations should be performed. Rather, while an example order is shown, it will be understood that the order of the operations can be modified, where appropriate. Thus, the operations shown may be modified, added, and / or omitted, and certain operations may be performed in a different order or simultaneously. Moreover, a person skilled in the art will understand that it is not necessary to perform all the operations described.

[0135] Furthermore, references to features and advantages, or similar language used throughout this specification, do not imply that all of the features and advantages that may be realized in the embodiments disclosed herein should or are present in any single embodiment. Rather, references to features and advantages are understood to mean that the particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment. Thus, references to features, advantages, and similar language used throughout this disclosure may, but do not necessarily, refer to the same embodiment.

[0136] Furthermore, the present disclosure includes embodiments according to the following clauses: Article 1. at least one joint (102) configured to transition between a clearance fit state and an interference fit state in response to a change in temperature; and A stationary isolator (100) comprising a dampener (104) configured to dampen transmission of vibration through the one or more joints (102) when the one or more joints (102) are in the clearance fit condition. Article 2. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); 2. The stationary isolator (100) of claim 1, comprising a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108). Article 3. the first portion (106) and the second portion (110) are fixed relative to one another below a transition temperature (114); 3. The stationary isolator (100) of claim 2, wherein the first portion (106) and the second portion (110) are movable relative to one another above the transition temperature (114). Article 4. the first portion (106) and the second portion (110) are movable relative to one another below a transition temperature (114); 3. The fixed isolator (100) of claim 2, wherein the first portion (106) and the second portion (110) are fixed relative to one another above the transition temperature (114). Article 5. 5. The stationary isolator (100) of any one of clauses 1 to 4, wherein the one or more joints (102) include a joint (102) configured to move linearly when in the clearance fit condition. Article 6. 6. The stationary isolator (100) of claim 5, wherein the joint (102) configured for linear movement includes a plain bearing. Article 7. 7. The stationary isolator (100) of any one of clauses 1 to 6, wherein the one or more joints (102) include a joint (102) configured for rotational movement when in the clearance fit condition. Article 8. 8. The stationary isolator (100) of claim 7, wherein the joint (102) configured for rotational movement includes a spherical bearing. Article 9. 9. The stationary isolator (100) of any one of clauses 1 to 8, further comprising a heating element (116) configured to heat the one or more joints (102). Article 10. a piezoelectric generator (118) configured to generate electrical power in response to mechanical strain; the piezoelectric generator (118) is in electrical communication with the heating element (116); 10. The stationary isolator (100) of claim 9, wherein the electrical power energizes the heating element (116). Article 11. 11. The stationary isolator (100) of claim 10, wherein the piezoelectric generator (118) comprises a piezoelectric cantilever (120) configured to bend in response to the vibration. Article 12. 12. The stationary isolator (100) of claim 11, wherein the piezoelectric cantilever (120) has a length L selected to resonate in a range of frequencies of vibration. Article 13. Base (122), a linkage (124) coupled to the base (122); a cap (126) coupled to the linkage (124) opposite the base; and a bumper (104) coupled to the base (122) and the cap (126); the linkage (124) is configured to transition between an unfixed state in which the cap (126) is movable relative to the base (122) and a fixed state in which the cap (126) is fixed relative to the base (122) in response to a change in temperature; The damper (104) is configured to damp the transmission of vibration between the base (122) and the cap (126) when the linkage (124) is in the unlocked state. Article 14. Clause 14. The stationary isolator (100) of clause 13, wherein the linkage (124) comprises one or more joints (102) configured to transition between a clearance fit state and an interference fit state in response to a change in temperature. Article 15. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); 15. The stationary isolator (100) of claim 14, comprising a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108). Article 16. The linkage (124) comprises one or more joints (102), and the linkage (124) comprises: a first link (128) coupled to the base (122) by a first joint (130) of the one or more joints (102); and a second link (132) coupled to the first link (128) by a second joint (134) of the one or more joints (102) opposite the base (122); The fixed isolator (100) of claim 13, wherein the cap (126) is coupled to the second link (132) on an opposite side to the first link (128) by a third joint (136) of the one or more joints (102). Article 17. above a first transition temperature (138), the first joint (130) has a clearance fit in which the first link (128) is movable relative to the base (122) or has an interference fit in which the first link (128) is fixed relative to the base (122); above a second transition temperature (140), the second joint (134) has the clearance fit condition in which the second link (132) is movable relative to the first link (128) or has the interference fit condition in which the second link (132) is fixed relative to the first link (128); 17. The fixed isolator (100) of claim 16, wherein above a third transition temperature (142), the third joint (136) has the clearance fit state in which the cap (126) is movable relative to the second link (132) or the interference fit state in which the cap (126) is fixed relative to the second link (132). Article 18. 18. The stationary isolator (100) of claim 17, wherein the first transition temperature (138), the second transition temperature (140), and the third transition temperature (142) are the same. Article 19. 18. The stationary isolator (100) of clause 17, wherein at least one of the first transition temperature (138), the second transition temperature (140), and the third transition temperature (142) is different from at least another one of the first transition temperature (138), the second transition temperature (140), and the third transition temperature (142). Article 20. the first joint (130) and the third joint (136) each include a spherical bearing; 20. The stationary isolator (100) of any one of clauses 17 to 19, wherein the second joint (134) comprises a plain bearing. Article 21. 21. The stationary isolator (100) of any one of clauses 13 to 20, further comprising a heating element (116) configured to effect a change in temperature. Article 22. 22. The stationary isolator (100) of claim 21, wherein the heating element (116) is in thermal communication with the linkage (124). Article 23. 23. The stationary isolator (100) of claim 21 or claim 22, wherein the heating element (116) includes at least one coil heater coupled to at least one of the linkage (124), the base (122), and the cap (126). Article 24. a piezoelectric generator (118) configured to generate electrical power in response to mechanical strain; the piezoelectric generator (118) is in electrical communication with the heating element (116); 23. The stationary isolator (100) of claim 21 or 22, wherein the electrical power energizes the heating element (116). Article 25. 25. The stationary isolator (100) of claim 24, wherein the piezoelectric generator (118) comprises a plurality of piezoelectric cantilevers (120), each of the plurality of piezoelectric cantilevers (120) configured to bend in response to the vibration. Article 26. 26. The stationary isolator (100) of claim 25, wherein each of the plurality of piezoelectric cantilevers (120) has a length L selected to resonate in a range of frequencies of vibration. Article 27. 27. The stationary isolator (100) of any one of clauses 13 to 26, wherein the shock absorber (104) includes an elastomeric member (158). Article 28. 28. The stationary isolator (100) of claim 27, wherein the shock absorber (104) forms a housing (144) about the linkage (124). Article 29. 29. The stationary isolator (100) of any one of clauses 13 to 28, wherein the shock absorber (104) comprises a spring (160). Article 30. the base (122) is configured to be coupled to a first structure (146); 30. The stationary isolator (100) of any one of clauses 13 to 29, wherein the cap (126) is configured to be coupled to a second structure (148). Article 31. A method (1000) of isolating a first structure (146) of a structural system (150) from a second structure (148) of the structural system (150), comprising: coupling said first structure (146) and said second structure (148) together using a fixed standoff (100); transitioning one or more joints (102) of the fixed isolator (100) between a clearance fit state in which the first structure (146) and the second structure (148) are movable relative to one another and an interference fit state in which the first structure (146) and the second structure (148) are fixed relative to one another in response to a change in temperature; and A method (1000) comprising, when the one or more joints (102) are in the clearance fit state, attenuating transmission of vibration between the first structure (146) and the second structure (148) using a damper (104) of the fixed isolator (100). Article 32. 32. The method (1000) of claim 31, further comprising heating the stationary isolator (100) to change the temperature. Article 33. 33. The method (1000) of claim 32, wherein heating the stationary isolator (100) comprises moving the structural system (150) from a first ambient temperature to a second ambient temperature higher than the first ambient temperature. Article 34. 32. The method (1000) of claim 31, further comprising cooling the stationary isolator (100) to change the temperature. Article 35. 35. The method (1000) of claim 34, wherein cooling the stationary isolator (100) comprises moving the structural system (150) from a first ambient temperature to a second ambient temperature less than the first ambient temperature. Article 36. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108); 33. The method (1000) of clause 31 or 32, wherein the method (1000) further comprises heating each joint (102) of the one or more joints (102) above a transition temperature (114) to expand the first portion (106) relative to the second portion (110) or to expand the second portion (110) relative to the first portion (106). Article 37. 37. The method (1000) of any one of clauses 31, 32, or 36, further comprising heating the one or more joints (102) using a heating element (116). Article 38. generating electrical power in response to mechanical strain using a piezoelectric generator (118); and 38. The method (1000) of claim 37, further comprising energizing the heating element (116) using the electrical power. Article 39. The piezoelectric generator (118) comprises a piezoelectric cantilever (120); 39. The method (1000) of claim 38, wherein generating the electrical power includes bending the piezoelectric cantilever (120) in response to the vibration. Article 40. 40. The method (1000) of claim 39, further comprising resonating the piezoelectric cantilever (120) in a range of frequencies of vibration.

[0137] The described features, advantages, and characteristics of an embodiment may be combined in any suitable manner in one or more other embodiments. Those skilled in the art will recognize that the embodiments described herein may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in a particular embodiment, but may not be present in all embodiments. Moreover, while various embodiments of the stationary isolator 100 and method 1000 have been shown and described, modifications will occur to those skilled in the art upon reading this specification. The application includes such modifications and is limited only by the scope of the claims.

Claims

1. one or more joints (102) configured to transition between a clearance fit state and an interference fit state in response to a change in temperature; a damper (104) configured to dampen transmission of vibration through the one or more joints (102) when the one or more joints (102) are in the clearance fit condition; a heating element (116) configured to heat the one or more joints (102) or a cooling element (162) configured to cool the one or more joints (102); and a piezoelectric generator (118) configured to generate electrical power in response to mechanical strain; the piezoelectric generator (118) is in electrical communication with the heating element (116) or the cooling element (162); the electrical power energizes the heating element (116) or the cooling element (162); The stationary isolator (100), wherein the piezoelectric generator (118) comprises a piezoelectric cantilever (120) configured to bend in response to the vibration.

2. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); The stationary isolator (100) of any preceding claim, comprising a second portion (110) having a second rate of thermal expansion (112) different than the first rate of thermal expansion (108).

3. the first portion (106) and the second portion (110) are fixed relative to one another below a transition temperature (114); The stationary isolator (100) of claim 2, wherein said first portion (106) and said second portion (110) are movable relative to one another above said transition temperature (114).

4. the first portion (106) and the second portion (110) are movable relative to one another below a transition temperature (114); The stationary isolator (100) of claim 2, wherein said first portion (106) and said second portion (110) are fixed relative to one another above said transition temperature (114).

5. A method (1000) of isolating a first structure (146) of a structural system (150) from a second structure (148) of said structural system (150), comprising: coupling said first structure (146) and said second structure (148) together using a fixed standoff (100); transitioning one or more joints (102) of the fixed isolator (100) from a clearance fit state in which the first structure (146) and the second structure (148) are movable relative to one another to an interference fit state in which the first structure (146) and the second structure (148) are fixed relative to one another in response to a first change in temperature; transitioning the one or more joints (102) from the interference fit condition to the clearance fit condition in response to a second change in temperature; and The method (1000) includes, in the clearance fit state of the one or more joints (102), attenuating transmission of vibration between the first structure (146) and the second structure (148) using a damper (104) of the fixed isolator (100).

6. The method (1000) of claim 5, further comprising heating the stationary isolator (100) to change the temperature.

7. The method (1000) of claim 5, further comprising cooling the stationary isolator (100) to vary the temperature.

8. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108); 7. The method (1000) of claim 5 or 6, further comprising heating each joint (102) of the one or more joints (102) above a transition temperature (114) to cause the first portion (106) to expand more than the second portion (110) or to cause the second portion (110) to expand more than the first portion (106).

9. 9. The method (1000) of any one of claims 5 to 8, further comprising heating the one or more joints (102) using a heating element (116) or cooling the one or more joints (102) using a cooling element (162).

10. generating electrical power in response to mechanical strain using a piezoelectric generator (118); and further comprising energizing the heating element (116) or the cooling element (162) using the electrical power; 10. The method (1000) of claim 9, wherein the piezoelectric generator (118) comprises a piezoelectric cantilever (120) configured to bend in response to the vibration.

11. Each joint (102) of the one or more joints (102) a first portion (106) having a first coefficient of thermal expansion (108); a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108); 8. The method (1000) of claim 5 or 7, further comprising cooling each joint (102) of the one or more joints (102) below a transition temperature (114) to cause the first portion (106) to shrink more than the second portion (110) or to cause the second portion (110) to shrink more than the first portion (106).

12. One or more joints (102) configured to transition between a clearance fit state and an interference fit state in response to a change in temperature; and a damper (104) configured to dampen transmission of vibration through the one or more joints (102) when the one or more joints (102) are in the clearance fit state; each joint (102) of the one or more joints (102) comprising a first portion (106) having a first coefficient of thermal expansion (108) and a second portion (110) having a second coefficient of thermal expansion (112) different from the first coefficient of thermal expansion (108); the first portion (106) and the second portion (110) are movable relative to one another below a transition temperature (114); The first portion (106) and the second portion (110) are fixed relative to one another above the transition temperature (114).

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