Test system with column cradle

Abstract

A testing machine (10; 10') includes: a base (12); at least one pair of columns (14) connected to the base (12); and a transverse carrier (16) connected to the columns (14) at a distance spaced from the base (12). At least one pair of sample holders (20A, 20B) are provided. A first sample holder (20A) is supported by the transverse carrier (16) and faces the base (12), and a second sample holder (20B) is supported by the base (12), which is the portion of the plurality of columns (14) closest to the transverse carrier (16). An actuator (22) is connected in series between one of the sample holders (20A, 20B) and the corresponding base (12) or transverse carrier (16). The bracket assembly (30; 56; 80) is connected to each of the plurality of columns (14) at a location along the length of each column (14) between the base (12) and the transverse carrier (16), the bracket assembly (30; 56; 80) spanning between the columns (14) to connect the columns (14) together or to connect the columns to the base (12) or the transverse carrier (16).

Description

Background Technology

[0001] The discussion below is provided for general background information only and is not intended to help determine the scope of the subject matter for which protection is sought.

[0002] Physical testing of materials and / or components is well known by taking a test specimen and applying tensile and / or compressive loads and / or displacements using an actuator. Typically, tensile and compressive loads are applied to the test specimen alternately at selected frequencies or at a constant displacement or amplitude through a series of frequencies. In harmonic motion (as in this form of testing), the acceleration of the moving parts of the actuator, the specimen clamp, etc., is proportional to the displacement multiplied by the square of the frequency. Therefore, even with a small amplitude (e.g., 0.06 mm), the acceleration can be very large at higher frequencies (e.g., 700 to 1000 Hz).

[0003] Therefore, as the frequency increases, the force, which is proportional to the mass of the moving part multiplied by the acceleration, also increases with the square of the frequency. Furthermore, this force must be reacted by the structure of the test system, which will induce the excitation of modes within the test system.

[0004] A typical testing machine includes a base with upright columns that support a transverse carrier head above the base. A first specimen clamp is connected to the transverse carrier head via a force sensor, while a second specimen clamp is connected to the base using an actuator; however, the positions of the actuator and the force sensor can be reversed.

[0005] Due to the large dynamic forces, vibrations may occur during operation. One vibration mode that has proven unfavorable for testing is the "box mode" excited in the box-like structure of the transverse carrier, base, and column. This mode is disadvantageous because these modes cause the force sensor (and / or displacement sensor) to move up and down, which introduces errors into its corresponding output signal(s). Summary of the Invention

[0006] This summary is provided to introduce some concepts in a simplified form, which are further described in the detailed embodiments below. This summary is not intended to define key, essential, or all features of the invention. Additionally, the descriptions and claimed subject matter provided herein should not be construed as addressing any shortcomings discussed in the background section.

[0007] A testing machine includes: a base; at least one pair of uprights connected to the base; and a transverse carrier connected to the uprights at a location spaced apart from the base. At least one pair of sample holders are provided. A first sample holder is supported by the transverse carrier and faces the base, and a second sample holder is supported by the base, which is the portion of each upright closest to the transverse carrier. An actuator is connected in series between one of the sample holders and its corresponding base or transverse carrier. A bracket is connected to each upright and spans between the uprights, the bracket being connected to each upright at a location between the base and the transverse carrier along the length of each upright.

[0008] The embodiments may include one or more of the following features. The bracket may be connected to each of the plurality of posts at multiple different locations. In a first embodiment, the bracket is connected to each of the plurality of posts between the farthest ends of the specimen holder, while in another embodiment, it may be preferred that the bracket is connected to each of the plurality of posts between the closest ends of the specimen holder.

[0009] Some preferred ranges include positioning the bracket to be attached to each of the plurality of posts at a location ranging from about 25% to 75% of the distance between the closest ends of the specimen holders. In another embodiment, the bracket is attached to each of the plurality of posts at a location ranging from about 40% to 60% of the distance between the closest ends of the specimen holders. The bracket may also be attached to each of the plurality of posts at about 50% of the distance between the closest ends of the specimen holders.

[0010] Each post includes an axis, and the bracket may include a portion extending along a plane parallel to the plane having the axis between the two posts. At each end of the bracket, portions are connected along a bisecting plane of each post to opposite sides of the outer surface of the respective post, the bisecting plane being normal to the plane extending between the posts. The bracket may include an orifice through which the axis between the specimen holders can extend. If desired, the bracket may include a removable portion defining a portion of the orifice, thereby allowing easy insertion and removal of the test specimen without removing or moving the bracket along the posts.

[0011] Typically, the testing machine includes at least one pair of columns, but may also include more columns, such as four. In the case of more than two columns, a second bracket may be connected between two columns different from the one connected to the first bracket, the second bracket being connected to each of the respective columns at least along the length of each of the columns between the distant ends of the specimen holders. Depending on the number of columns, the testing machine may include a third and a fourth bracket, each of the brackets connected to adjacent columns surrounding an outer perimeter that surrounds an axis extending between the specimen holders.

[0012] The column can extend through the base. In this embodiment, the ends of the column on the side of the base away from the transverse carrier are connected together. Similarly, the column can extend through the transverse carrier, wherein the ends of the column on the side of the transverse carrier away from the base are connected together.

[0013] The testing machine further includes: a base; at least one pair of columns connected to the base; a transverse carrier connected to the columns at a distance spaced from the base; at least one pair of sample holders, wherein a first sample holder is supported by the transverse carrier and faces the base, and a second sample holder is supported by the base, which is the portion of each of the plurality of columns closest to the transverse carrier; and an actuator connected in series between one of the sample holders and the corresponding base or transverse carrier.

[0014] A testing machine includes: a base; at least one pair of uprights connected to the base; and a transverse carrier connected to the uprights at a location spaced apart from the base. At least one pair of sample holders are provided. A first sample holder is supported by the transverse carrier and faces the base, and a second sample holder is supported by the base, which is the portion of the plurality of uprights closest to the transverse carrier. An actuator is connected in series between one of the sample holders and its corresponding base or transverse carrier. A bracket assembly is connected to each of the uprights at a location along the length of each upright between the base and the transverse carrier, the bracket assembly spanning across the uprights to connect the uprights together or to the base or transverse carrier. In a first embodiment, the bracket is connected to the uprights at a location spaced apart from the base and the transverse carrier and spans across the uprights. Additionally or alternatively, the bracket assembly may include a brace attached to each post, wherein a first end of the brace is attached to the post and a second end is attached to the base or lateral carrier. Attached Figure Description

[0015] Figure 1 This is a side view of the testing machine.

[0016] Figure 2 This is an enlarged view of a part of the testing machine.

[0017] Figure 3 This is a 3D view of a part of the testing machine.

[0018] Figure 4 It is the edge of the testing machine Figure 3 The cross-sectional view taken by section line IV-IV.

[0019] Figure 5 This is a graphical representation of the deformation of the testing machine at a selected frequency without a column support.

[0020] Figure 6 It is a graphical representation of the deformation of the testing machine at a selected frequency when there is a column bracket.

[0021] Figure 7 The chamber modal resonance frequencies of specimens of different lengths are shown.

[0022] Figure 8 It is a schematic diagram showing the column bracket. Detailed Implementation

[0023] Figure 1 The diagram shows a schematic of a testing machine 10 for applying force or motion to a test specimen (not shown). The testing machine includes a frame 11 having a base 12, a pair of uprights 14 extending upward from the base 12, and a transverse carrier 16 connecting the two uprights 14 at a spaced distance from the base 12. At least one pair of specimen holders 20A and 20B are provided. The first specimen holder 20A is supported by the transverse carrier 16 and extends toward the base 12. The second specimen holder 20B is supported by the base 12 and extends toward the transverse carrier 16. It should be noted that the base 12 is the portion of the testing machine 10 closest to the transverse carrier 16, connecting to each of the plurality of uprights 14.

[0024] Actuator 22 is connected in series between one of the sample holders 20A, 20B and the corresponding base 12 or transverse carrier 16. In the illustrated embodiment, the first sample holder 20A is connected to a force sensor 24 supported by the transverse carrier 16, while the second sample holder 20B is connected to actuator 22 in the base 12. It should be noted that in another embodiment, actuator 22 is positioned in the transverse carrier 16, and force sensor 24 is then connected to the base 12.

[0025] refer to Figure 3 and Figure 4This document illustrates a bracket assembly, 30, connected to and spanning a plurality of columns 14. The bracket 30 is connected to one of the columns 14 at a location along its length between the base 12 and the transverse carrier 16. The test chamber 10 exhibits several resonant vibration modes. One important vibration mode is commonly referred to as the "box mode." By adding, for example, the bracket 30 connecting the columns 14 approximately between the base 12 and the transverse carrier 16, at the center of the span of the columns 14, the box mode frequency is significantly increased compared to a test chamber without the bracket 30. Figure 5 and Figure 6 The test machine 10 with and without the bracket 30 are shown graphically in enlarged form. Figure 5 In the test machine 10 without the bracket 30, significant deformation occurs approximately at the center of the span of the column 14, with the deformation decreasing as it extends downward toward the base 12 and upward toward the transverse carrier 16.

[0026] exist Figure 6 In the middle, bracket 30 extends between columns 14. Although additional deformation may exist in the transverse carrier 16, the deformation of the columns 14 at the center of the span has been significantly reduced. More importantly, the modal resonant frequency of the enclosure has increased from approximately 715 Hz without bracket 30 to approximately 824 Hz with bracket 30. Figure 7 The chamber modal resonance frequencies of specimens of different lengths are shown.

[0027] Although Figure 3 and Figure 6 The diagram shows the bracket 30 positioned approximately at the center of the span of the column 14, but it may also be advantageous to position the bracket at other locations along the column 14. Typically, the bracket 30 is connected to the column at some point along the length of each of the plurality of columns 14 between the farthest ends of the specimen holders 20A, 20B. In another embodiment, the bracket 30 is connected to each of the plurality of columns 14 between the closest ends of the specimen holders 20A, 20B. In yet another embodiment, the bracket 30 is connected to each of the plurality of columns 14 at a location ranging from approximately 25% to approximately 75% of the distance between the closest ends of the specimen holders 20A, 20B. In yet another embodiment, the bracket 30 is connected to each of the plurality of columns at a location and range ranging from approximately 40% to 60% of the distance between the closest ends of the specimen holders 20A, 20B. The bracket 30 can also be connected to each of the plurality of columns 14 at approximately 50% of the distance between the closest ends of the sample holders 20A and 20B to each other.

[0028] Each column 14 includes an axis 32, and the bracket 30 includes a portion 40 extending along a plane 41 between the columns 14 parallel to a plane 43 having the axes 32 of the two columns 14. In one embodiment, the portion 40 at each end of the bracket 30 is attached at a bisecting plane 45 of each column 14 to opposite sides of the outer surface of each corresponding column 14, the bisecting plane 45 being normal to the plane 43 extending between the columns 14. It is believed that positioning or attaching the bracket 30 to the outer surface of the column 14 at a location coinciding with the bisecting plane 45 provides maximum stiffness to the column 14. Typically, the bracket 30 is mounted to the column 14 to provide a structural element, such as the portion 40, extending in a plane perpendicular to the axis of the column 14.

[0029] refer to Figure 4 The bracket 30 may include an orifice 42 and an axis 44 between the sample holders 20A and 20B. Figure 2 The orifice 42 extends through the support. The orifice 42 thus allows the test specimen to be attached along axis 44 to the specimen holders 20A, 20B without contacting a portion of the support 30. The size of the orifice 42 allows the end of the test specimen to extend through the orifice 42 during loading, and the end of the test specimen can then be attached to each of the other specimen holders 20A, 20B. It should be noted that in the exemplary embodiment, the column 14 has a relatively large diameter, which may be wider than the test specimen to be tested; however, the configuration of the support 30 shown should not be limiting, as the support 30 may have an orifice approximately the same size as the diameter of the column 14 or a larger orifice than the diameter of the column. In such cases, if desired, the portion of the support 30 extending between the columns 14 may be bent outward in one or both directions indicated by the double arrows 47 to provide a larger orifice.

[0030] In another embodiment, a portion 46 of the outer periphery of the defining orifice 42 of the bracket 30 is removable to allow the test specimen to be inserted into or removed from the orifice 42. Once the test specimen has been mounted to the specimen holders 20A, 20B, portion 46 is reattached. The removable portion 46 can be connected to other portions of the bracket 30 using suitable fasteners 48, such as bolts. In another embodiment, portion 46 may be hinged at one end, so that only one fastener is needed to secure portion 46 to the other portions of the bracket 30.

[0031] The ends 30A, 30B of the bracket are fastened to the post 14, for example, on the outer surface of the post. In one embodiment, each of the ends 30A, 30B includes a clamp that clamps onto the outer surface of the post 14. For example, the clamp at each end 30A, 30B may include a split collar having one or more suitable fasteners 51, such as bolts or the like, which causes the inner diameter of the bracket 30 to contract or expand (or the separate portions may be mounted together) to clamp onto the outer surface of the post 14.

[0032] It should be noted that the bracket 30 disclosed herein is not limited to a testing machine with only one pair of columns, but can be used with other multi-column testing machines. Figure 8 This is a schematic top cross-sectional view of a testing machine 10' having four columns 14. In this testing machine, multiple brackets 52, 53, 54, and 55 (similar to bracket 30) are used between adjacent columns 14 to form a structure 56 having multiple brackets 52 to 55 spanning between adjacent columns. Additionally or alternatively, brackets 58, 59 may extend between non-adjacent columns 14, for example, diagonally when the four columns 14 are arranged in a square or rectangle. The diagonally extending brackets 58, 59 will therefore potentially extend or bisect the test specimen axis extending between the specimen holders; and therefore, brackets 58, 59 may also include orifices, such as orifices 42 in bracket 30.

[0033] Come back for reference Figure 1 The testing machine 10 has a column 14 extending through a base 12 to a connecting element 70, the connecting element being attached to the end of the column 14 on the side of the base 12 away from the transverse carrier 16. Similarly, if desired, the column 14 can extend through the transverse carrier 16 as shown by the dashed line and can be connected to the structural element 72 at the end of the column away from the base 12. Figure 1 In one embodiment, the base 12 is movable along the column 14 and selectively secured to the column by clamping devices 80, which include pneumatic or hydraulic actuators that clamp portions of the base 12 to the outer surface of the column 14. The base 12 is adjustable to change the distance between the specimen holders 20A and 20B according to the length of the test specimen being tested.

[0034] Figure 3Another form of the bracket assembly 80 is shown, which includes one or more braces 81, 82, 83, 84 (schematically depicted) connected to the column 14 at a first portion, at a location indicated on the front, such as at the center of the span between the base 12 and the transverse carrier 16, or approximately at the center of the span between the base and the transverse carrier. Braces 81 to 84 can be mounted to the column 14 using split neck rings as found in bracket 30. As shown, braces 81 to 84 are also securely fastened to the base 12, but these braces can be secured to the transverse carrier 16 if desired.

[0035] Although the subject matter of the invention has been described in language relating to specific environments, structural features, and / or methodological actions, it should be understood that the subject matter of the invention as defined in the appended claims is not limited to the environments, specific features, or actions described above as established by the courts. Rather, the environments, specific features, and actions described above are disclosed as examples of implementing the claims.

Claims

1. A testing machine, comprising: Base; At least one pair of uprights, the at least one pair of uprights being connected to the base; A transverse carrier head, which is connected to the column at a position spaced apart from the base; At least one pair of specimen holders, wherein a first specimen holder is supported by the transverse carrier head and faces the base, and a second specimen holder is supported by the base, which is the portion of each of the columns closest to the transverse carrier head. An actuator, wherein the actuator is connected in series between one of the at least one pair of specimen holders and the corresponding base or lateral carrier; and A bracket, connected to and spanning across the at least one pair of uprights, is attached to each of the at least one pair of uprights at a location along the length of each upright between the base and the transverse carrier. The bracket includes an orifice through which the axis between the sample holders extends, and the bracket includes a removable portion defining a portion of the orifice.

2. The testing machine as described in claim 1, wherein, The bracket is connected between the far ends of the specimen holder to each of the at least one pair of columns.

3. The testing machine as described in claim 1, wherein, The bracket is connected between the closest ends of the specimen holder to each of the at least one pair of columns.

4. The testing machine as described in claim 1, wherein, The bracket is connected to each of the at least one pair of posts at a location ranging from 25% to 75% of the distance between the closest ends of the specimen holders.

5. The testing machine as described in claim 4, wherein, The bracket is connected to each of the at least one pair of posts at a location ranging from 40% to 60% of the distance between the closest ends of the sample holders.

6. The testing machine as described in claim 5, wherein, The bracket is connected to each of the at least one pair of posts at 50% of the distance between the closest ends of the sample holders.

7. The testing machine as described in claim 1, wherein, Each column includes an axis, and the bracket includes a portion extending along a plane between the columns that is parallel to the plane of the axis having two columns.

8. The testing machine as described in claim 7, wherein, A portion at each end of the bracket is connected along a bisecting plane of each column to opposite sides of the outer surface of the respective column, the bisecting plane being perpendicular to the plane extending between the columns.

9. The testing machine as described in claim 1, wherein, The at least one pair of columns includes four columns and a second bracket, different from the bracket, connected between two columns. The second bracket is connected to each of the respective columns at a position along the length of each of the respective columns between the distant ends of the specimen holder.

10. The testing machine of claim 9, further comprising a third bracket and a fourth bracket, each of the brackets connecting adjacent columns around an outer perimeter extending between the sample holders.

11. The testing machine as described in claim 1, wherein, The actuator is disposed in the base.

12. The testing machine as described in claim 11, wherein, The column extends through the base.

13. The testing machine as described in claim 12, wherein, The ends of the column on the side of the base away from the transverse carrier are connected together.

14. The testing machine as described in claim 1, wherein, The actuator is disposed in the transverse carrier head.

15. The testing machine as described in claim 14, wherein, The column extends through the transverse carrier.

16. The testing machine as described in claim 15, wherein, The ends of the column on the side of the transverse carrier away from the base are connected together.

17. A testing machine, comprising: Base; At least one pair of uprights, the at least one pair of uprights being connected to the base; A transverse carrier head, which is connected to the column at a position spaced apart from the base; At least one pair of specimen holders, wherein a first specimen holder is supported by the transverse carrier head and faces the base, and a second specimen holder is supported by the base, which is the portion of each of the at least one pair of posts closest to the transverse carrier head. An actuator, wherein the actuator is connected in series between one of the at least one pair of specimen holders and the corresponding base or lateral carrier; and A bracket assembly is connected to each of the at least one pair of uprights at a location along the length of each upright between the base and the transverse carrier, the bracket assembly spanning between the uprights to connect the uprights together or to the base or the transverse carrier. The bracket assembly includes an orifice through which the axis between the sample holders extends, and the bracket assembly includes a removable portion defining a portion of the orifice.

18. The testing machine as described in claim 17, wherein, The bracket assembly includes a bracket that is connected to the uprights at a location spaced apart from the base and the transverse carrier and spans between the uprights.

19. The testing machine as described in claim 17, wherein, The bracket assembly includes a corner brace connected to each column, wherein a first end of the corner brace is connected to the column and a second end is connected to the base or the transverse carrier.

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