Tension testing tool and related systems and methods

Abstract

The present application relates to tension testing tools and related systems and methods. Disclosed herein is a tension testing tool and related systems and methods for evaluating mechanical properties of a composite test specimen under combined axial and bending loads. The tension testing tool includes a first test fixture and a second test fixture arranged in mirror orientation across a center plane, each test fixture having a main body and a back plate to secure a test specimen. A load application arm is attached to each test fixture via an arm attachment opening. The test fixtures are configured to be removably secured to a test frame that applies a force along a longitudinal axis to at least one of the load application arms to assess interlaminar strength, deformation behavior, and failure mechanisms in the test specimen.

Description

Technical Field

[0001] This disclosure generally relates to material testing systems, and more specifically to tension testing tools for evaluating the mechanical properties of test samples. Background Technology

[0002] Due to the lightweight, high strength, and energy-absorbing properties of complex composite components, industries such as aerospace are experiencing a rapid increase in demand. Assessing the mechanical properties of these advanced structures is crucial for ensuring their performance and reliability. However, traditional testing methods for composite structures are often time-consuming, expensive, and designed for small sample sizes. Therefore, these methods may not adequately account for the structural behavior of larger composite components with complex geometries and large radii. Consequently, traditional testing methods may introduce artificial constraints or fail to reflect real-world loading conditions, leading to inaccurate or incomplete results. Summary of the Invention

[0003] The subject matter of this application was developed in response to the current state of the art, and in particular in response to the shortcomings of material testing systems and methods that are not yet fully addressed by currently available technologies. Therefore, the subject matter of this application is developed to provide a tension testing tool, as well as related systems and methods, which overcome at least some of the aforementioned shortcomings of the prior art.

[0004] The following is a non-exhaustive list of examples of the topics disclosed in this article, which may or may not require protection.

[0005] This document discloses a tension testing tool comprising a first test fixture and a second test fixture. Each test fixture includes a body having an arm attachment opening and a first retaining surface. Each test fixture also includes a back plate having a second retaining surface. Fasteners are configured to removably secure the back plate to the body. A load-applying arm is removably attached to the arm attachment opening of the body. When the fasteners removably secure the back plate to the body, the first retaining surface of the body and the second retaining surface of the back plate are spaced apart and face each other. A gap is defined between the first and second retaining surfaces. This gap is configured to receive and retain a test sample. The first and second test fixtures are spaced apart across a central plane and mirror each other. The foregoing subject matter of this paragraph characterizes Example 1 of this disclosure.

[0006] At least one of the first test fixtures is configured to move along a longitudinal axis in a first direction perpendicular to the central plane in response to a first applied force, and the second test fixture is configured to move along a longitudinal axis in a second direction opposite to the first direction in response to a second applied force equal to the first applied force. The foregoing subject matter of this paragraph characterizes Example 2 of this disclosure, wherein Example 2 also includes the subject matter according to Example 1 described above.

[0007] Each of the first and second test fixtures includes a pin configured to extend through an arm attachment opening in the body and an opening in the load application arm. The foregoing subject matter of this paragraph characterizes Example 3 of this disclosure, wherein Example 3 also includes subject matter according to any one of Examples 1-2 above.

[0008] For each of the first and second test fixtures, the load application arm is pivotable relative to the body when it is attached to the arm attachment opening of the body. The foregoing subject matter of this paragraph characterizes Example 4 of this disclosure, wherein Example 4 also includes subject matter according to any one of Examples 1-3 above.

[0009] Each of the first and second test fixtures includes a plurality of arm attachment openings. The arm attachment opening is one of the plurality of arm attachment openings. The foregoing subject matter of this paragraph characterizes Example 5 of this disclosure, wherein Example 5 also includes subject matter according to any one of Examples 1-4 above.

[0010] For each of the first and second test fixtures, the arm attachment opening includes a first arm attachment opening and a second arm attachment opening. The first arm attachment opening is positioned further away from the first holding surface of the body than the second arm attachment opening. The foregoing subject matter of this paragraph characterizes Example 6 of this disclosure, wherein Example 6 also includes subject matter according to any one of Examples 1-5 above.

[0011] For at least one of the first and second test fixtures, when the load application arm is attached to the first arm attachment opening, the force applied to the load application arm is transmitted through the body as a combination of a first bending and axial load. When the load application arm is attached to the second arm attachment opening, the force applied to the load application arm is transmitted through the body as a combination of a second bending and axial load. The first bending and axial loads are different from the second bending and axial loads. The foregoing subject matter of this paragraph characterizes Example 7 of this disclosure, wherein Example 7 also includes the subject matter according to Example 6 described above.

[0012] The first retaining surface of the body of the first test fixture is positioned at an oblique angle relative to the first retaining surface of the body of the second test fixture. The foregoing subject matter of this paragraph characterizes Example 8 of the present disclosure, wherein Example 8 also includes subject matter according to any one of Examples 1-7 above.

[0013] The first and second test fixtures are configured to be repositioned relative to each other while maintaining a mirror orientation across the central plane. The foregoing subject matter of this paragraph characterizes Example 9 of this disclosure, wherein Example 9 also includes subject matter according to any one of Examples 1-8 above.

[0014] This document further discloses a tension testing system comprising a first test fixture and a second test fixture. Each test fixture includes a body having an arm attachment opening and a first retaining surface, a back plate having a second retaining surface, fasteners configured to removably secure the back plate to the body, and a load application arm capable of removably attaching to the arm attachment opening of the body. The system also includes a test frame. During testing, the first and second test fixtures are removably secured to the test frame such that the first and second test fixtures are spaced apart across a central plane and mirror each other. The first retaining surface of the body of the first test fixture is positioned at an oblique angle relative to the first retaining surface of the body of the second test fixture. A first attachment portion of the test sample is removably secured between the first retaining surface of the body of the first test fixture and the second retaining surface of the back plate. A second attachment portion of the test sample is removably secured between the first retaining surface of the body of the second test fixture and the second retaining surface of the back plate. The first and second attachment portions are spaced apart by a middle test portion of the test sample. The test frame applies a force along its longitudinal axis to at least one of the load-applying arms of the first and second test fixtures to evaluate the mechanical properties of the test sample. The foregoing subject matter of this paragraph characterizes Example 10 of this disclosure.

[0015] At least one of the first test fixtures is configured to move along a longitudinal axis in a first direction perpendicular to the central plane in response to a first applied force, and / or the second test fixture is configured to move along a longitudinal axis in a second direction opposite to the first direction in response to a second applied force equal to the first applied force. The foregoing subject matter of this paragraph characterizes Example 11 of this disclosure, wherein Example 11 also includes the subject matter according to Example 10 described above.

[0016] The first and second test fixtures are adjustable in position relative to the test frame and relative to each other to accommodate test samples of various sizes. The foregoing subject matter of this paragraph characterizes Example 12 of this disclosure, wherein Example 12 also includes subject matter according to any one of Examples 10-11 above.

[0017] The test framework includes a load application system configured to control the magnitude of the force and the rate at which the force is applied to at least one of the load application arms of a first test fixture and a second test fixture. The foregoing subject matter of this paragraph characterizes Example 13 of this disclosure, wherein Example 13 also includes subject matter according to any one of Examples 10-12 above.

[0018] Each of the first and second test fixtures includes a plurality of arm attachment openings. The arm attachment opening is one of the plurality of arm attachment openings. The foregoing subject matter of this paragraph characterizes Example 14 of this disclosure, wherein Example 14 also includes subject matter according to any one of Examples 10-13 above.

[0019] Each of the first and second test fixtures is capable of being positioned relative to each other within the test frame with different mirror orientations. The tension testing system is configured to operate in at least one of an axially dominant condition, a balanced load condition, or a bending dominant condition. Operation in one of these conditions is based at least in part on the mirror orientation of the first and second test fixtures relative to the test frame and on a selected arm attachment opening to which the load application arm is attached. The foregoing subject matter of this paragraph characterizes Example 15 of this disclosure, wherein Example 15 also includes the subject matter according to Example 14 described above.

[0020] This document further discloses a method for performing a tension test on a test specimen, the method comprising attaching a first load-applying arm to the body of a first test fixture via an arm attachment opening in each body, and attaching a second load-applying arm to the body of a second test fixture. The method further comprises removably securing the first and second test fixtures to a test frame such that the first and second test fixtures are spaced apart across a central plane and mirror each other. The method further comprises securing a first attachment portion of the test specimen between a first holding surface of the body of the first test fixture and a second holding surface of the back plate of the first test fixture. Furthermore, the method comprises securing a second attachment portion of the test specimen between the first holding surface of the body of the second test fixture and the second holding surface of the back plate of the second test fixture. The first and second attachment portions are spaced apart by a middle test portion of the test specimen. The method concludes by applying a force along a longitudinal axis to at least one of the first and second load-applying arms to assess the mechanical properties in the test specimen. The foregoing subject matter of this paragraph characterizes Example 16 of this disclosure.

[0021] Each of the first and second test fixtures includes a plurality of arm attachment openings, wherein the arm attachment opening is one of these plurality of openings. Each arm attachment opening in the first test fixture has a corresponding arm attachment opening in the second test fixture positioned in a mirror orientation across a central plane. The step of attaching the first load-applying arm and the second load-applying arm includes attaching the first load-applying arm to a selected arm attachment opening in the first test fixture and attaching the second load-applying arm to a corresponding arm attachment opening in the second test fixture. The foregoing subject matter of this paragraph characterizes Example 17 of this disclosure, wherein Example 17 also includes the subject matter according to Example 16 described above.

[0022] The method includes selecting a first test fixture and a second test fixture in a mirror orientation relative to a test frame. The step of applying a force to at least one of a first load-applying arm and a second load-applying arm is based, at least in part, on the mirror orientation of the first and second test fixtures relative to the test frame and on a selected arm attachment opening to which the load-applying arm is attached, resulting in at least one of an axially dominant condition, a balanced load condition, or a bending-dominant condition. The foregoing subject matter of this paragraph characterizes Example 18 of this disclosure, wherein Example 18 also includes the subject matter according to Example 17 described above.

[0023] The steps of applying force include controlling the magnitude of the force and the rate at which the force is applied to at least one of the load application arms of the first test fixture and the second test fixture. The foregoing subject matter of this paragraph characterizes Example 19 of this disclosure, wherein Example 19 also includes the subject matter according to any one of Examples 16-18 above.

[0024] The method includes adjusting the positions of the first and second test fixtures relative to each other and relative to the test frame to accommodate the size of the test sample. The foregoing subject matter of this paragraph characterizes Example 20 of this disclosure, wherein Example 20 also includes subject matter according to any one of Examples 16-19 above.

[0025] In the tension testing system (200), at least one of the following is provided: the first test fixture (102) is configured to move along the longitudinal axis (126) in a first direction perpendicular to the central plane (122) in response to a first applied force; and the second test fixture (104) is configured to move along the longitudinal axis (126) in a second direction opposite to the first direction in response to a second applied force equal to the first applied force.

[0026] In the tension testing system (200), the first test fixture (102) and the second test fixture (104) can be adjusted and positioned relative to the test frame (210) and relative to each other to accommodate test samples (202) of various sizes.

[0027] The test frame (210) in the tension testing system (200) includes a load application system (212) configured to control the magnitude of the force and the rate at which the force is applied to at least one of the load application arms (120) of the first test fixture (102) and the load application arms (120) of the second test fixture (104).

[0028] Each of the first test fixture (102) and the second test fixture (104) in the tension testing system (200) includes a plurality of arm attachment openings (110), wherein the arm attachment opening (110) is one of the plurality of arm attachment openings.

[0029] In the tension testing system (200): the first test fixture (102) and the second test fixture (104) are capable of being positioned relative to each other with different mirror orientations relative to the test frame (210); the tension testing system is configured to operate in at least one of an axially dominant condition, a balanced load condition, or a bending dominant condition; and the operation of the tension testing system in at least one of the axially dominant condition, the balanced load condition, or the bending dominant condition is based at least in part on the mirror orientation of the first test fixture (102) and the second test fixture (104) relative to the test frame (210) and a selected arm attachment opening among the arm attachment openings to which the load application arm (120) is attached.

[0030] A method (300) for performing a tension test on a test sample (202), the method (300) comprising: attaching (302) a first load-applying arm (120) to (302) the body (108) of a first test fixture (102) via an arm attachment opening (110) in each body (108) and attaching a second load-applying arm (120) to the body (108) of a second test fixture (104); removably securing (304) the first test fixture (102) and the second test fixture (104) to a test frame (210) such that the first test fixture (102) and the second test fixture (104) are spaced apart across a central plane (122) and mirror each other; securing (306) a first attachment portion (204) of the test sample (202) to the first test fixture (102) of the body (108). Between the first holding surface (112) of the body (108) and the second holding surface (116) of the back plate (114) of the first test fixture (102); fixing (308) the second attachment portion (206) of the test sample (202) between the first holding surface (112) of the body (108) and the second holding surface (116) of the back plate (114) of the second test fixture (104), the first attachment portion (204) being spaced apart from the second attachment portion (206) by the intermediate test portion (208) of the test sample (202); and applying (310) a force along the longitudinal axis to at least one of the first load application arm (120) and the second load application arm (120) to evaluate the mechanical properties in the test sample (202).

[0031] In the method (300): each of the first test fixture (102) and the second test fixture (104) includes a plurality of arm attachment openings (110), wherein the arm attachment opening (110) is one of the plurality of arm attachment openings; each of the arm attachment openings (110) in the first test fixture (102) has a corresponding arm attachment opening positioned in a mirror orientation across the central plane (122) in the arm attachment opening (110) in the second test fixture (104); and the step of attaching the first load application arm (120) and the second load application arm (120) further includes attaching the first load application arm (120) to a selected arm attachment opening in the arm attachment opening (110) in the first test fixture (102) and attaching the second load application arm (120) to a corresponding arm attachment opening in the arm attachment opening (110) in the second test fixture (104).

[0032] The method (300) further includes selecting a mirror orientation of the first test fixture (102) and the second test fixture (104) relative to the test frame (210); wherein the step of applying the force to at least one of the first load application arm (120) and the second load application arm (120) is based at least in part on the mirror orientation of the first test fixture (102) and the second test fixture (104) relative to the test frame (210) and the selected arm attachment opening in the arm attachment opening (110) to which the first load application arm and the second load application arm are attached, resulting in at least one of an axially dominant condition, a balanced load condition, or a bending dominant condition.

[0033] In the method (300), the step of applying the force further includes controlling the magnitude of the force and the rate at which the force is applied to at least one of the load application arm (120) of the first test fixture (102) and the load application arm (120) of the second test fixture (104).

[0034] The method (300) further includes adjusting the positions of the first test fixture (102) and the second test fixture (104) relative to each other and relative to the test frame (210) to accommodate the size of the test sample (202).

[0035] The features, structures, advantages, and / or characteristics described in this disclosure can be combined in any suitable manner in one or more examples and / or embodiments. Numerous specific details are provided in the following description to impart a thorough understanding of the examples of this disclosure. Those skilled in the art will recognize that the subject matter of this disclosure can be practiced without one or more specific features, details, components, materials, and / or methods of a particular example or embodiment. In other instances, additional features and advantages may be recognized in certain examples and / or embodiments that may not be present in all examples or embodiments. Furthermore, in some cases, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the subject matter of this disclosure. The features and advantages of the subject matter of this disclosure will become more apparent from the following description and the appended claims, or may be learned through practice of the subject matter described below. Attached Figure Description

[0036] To more readily understand the advantages of this subject matter, a more specific description of the subject matter, briefly outlined above, will be provided with reference to the concrete examples illustrated in the accompanying drawings. It should be understood that these drawings, not necessarily drawn to scale, depict only certain examples of the subject matter and should not be considered as a limitation of its scope. The subject matter will be described and explained with additional specificity and detail using the accompanying drawings, wherein: Figure 1 This is a schematic side view of one example of a tension testing tool according to one or more examples of this disclosure, wherein a first test fixture and a second test fixture are spaced apart across a central plane; Figure 2 Based on one or more examples of this disclosure Figure 1 A schematic side view of the main body and load application arm of the first test fixture; Figure 3A Based on one or more examples of this disclosure Figure 1 A schematic side view of the back plate of the first test fixture; Figure 3B It is based on one or more examples of this disclosure. Figure 3A A schematic rear view of the back panel; Figure 4A This is a schematic side view of one example of a tension testing tool according to one or more examples of this disclosure, wherein the test sample is fixed within a first test fixture and a second test fixture, and the tension testing tool is in an axially dominant state; Figure 4B Based on one or more examples of this disclosure Figure 4A A schematic side view of a tension testing tool, wherein the tension testing tool is in a balanced load state; Figure 4CBased on one or more examples of this disclosure Figure 4A A schematic side view of a tension testing tool, wherein the tension testing tool is in a bending-dominant state; Figure 5 This is a schematic perspective view of one example of a tension testing system according to one or more examples of the present disclosure, wherein a tension testing tool is fixed to a test frame and a test sample is fixed inside the tension testing tool; Figure 6A This is a schematic partial perspective view of a test sample within a tension testing tool prior to a test operation, based on one or more examples of this disclosure. Figure 6B Based on one or more examples of this disclosure, Figure 6A A schematic perspective partial view of the test sample inside the tension testing tool after the test operation, depicting the deformation of the test sample; and Figure 7 This is a schematic flowchart of a method for performing a tension test on a test sample according to one or more examples of this disclosure. Detailed Implementation

[0037] Throughout this specification, references to “an example,” “example,” or similar language mean that a particular feature, structure, or characteristic described in connection with that example is included in at least one example of this disclosure. The phrases “in an example,” “in the example,” and similar language appearing throughout this specification may, but do not necessarily, refer to the same example. Similarly, the use of the term “implementation” means an implementation having a particular feature, structure, or characteristic described in connection with one or more examples of this disclosure; however, unless there is an explicit relevance indicating otherwise, an implementation may be associated with one or more examples.

[0038] This paper discloses a tension testing tool for evaluating the mechanical properties of test samples, as well as related systems and methods utilizing this tension testing tool. The tension testing tool is designed to test composite structures with complex and / or large radii. Such composite structures may experience a combination of axial and bending loads under real-world conditions, which can lead to interlaminar tensile stress, delamination, and other failure mechanisms important to the structural integrity of the composite structure. Evaluating the mechanical response of composite structures under representative load conditions can provide valuable insights into their performance in real-world applications. Traditional testing methods often focus on rotational forces and fail to adequately capture the interaction between bending and axial forces in larger composite structures, potentially limiting their ability to reflect real-world structural behavior. The disclosed example of a tension testing tool addresses these limitations by providing a controlled evaluation of the mechanical properties of composite structures under combined load conditions.

[0039] According to some examples, tension testing tools include two test clamps arranged in a mirror orientation relative to each other. A force is applied to at least one of the test clamps, which transmits the force to the test specimen to induce bending and axial loading, thereby evaluating the mechanical properties of the test specimen. The modular and scalable design of tension testing tools enables various testing configurations by combining repositionable test clamps and / or at least one of multiple arm attachment openings. These features facilitate characterizing different bending to axial force ratios and allow the tension testing tool to accommodate test specimens of different sizes. By providing a flexible and cost-effective solution, tension testing tools improve the accuracy and reliability of composite material evaluation.

[0040] according to Figure 1 An example of a tension testing tool 100 is shown. The tension testing tool 100 is configured to removably fix a test sample to assess the mechanical properties of the test sample. As used herein, in some examples, mechanical properties refer to the physical and structural properties of a material or component that affect its performance under applied forces. Mechanical properties may include, but are not limited to, interlaminar tensile (ILT) strength, flexural strength, axial load capacity, stiffness, and overall load-bearing behavior. Mechanical properties may also include failure mechanisms associated with delamination, crack propagation, and interlaminar stress distribution under combined loading conditions.

[0041] The tension testing tool 100 includes a first test fixture 102 and a second test fixture 104. The first test fixture 102 and the second test fixture 104 (collectively referred to as "test fixtures 102, 104") are spaced apart across a central plane 122 and arranged in a mirror orientation. Mirror orientation refers to the symmetrical arrangement of the test fixtures 102, 104 across the central plane 122, such that each fixture is positioned on opposite sides of the central plane 122, with corresponding structural features facing each other (e.g., equally spaced and oriented relative to the central plane 122). This arrangement helps ensure that when a force is applied to the test fixtures 102, 104, the resulting load is distributed evenly across the test sample, achieving uniform tension testing. The spacing between the test fixtures 102, 104 adapts to the test sample while maintaining alignment along a longitudinal axis 126 perpendicular to the central plane 122.

[0042] Each of the first test fixture 102 and the second test fixture 104 includes a body 108. That is, the first test fixture 102 includes a first body 108A, and the second test fixture 104 includes a second body 108B. The body 108 is the main structural component for securing and supporting the test sample during testing. The body 108 includes a first retaining surface 112, which serves as a contact surface for securing the test sample to a corresponding one of the test fixtures 102, 104. The first retaining surface 112 is positioned on one side of the body 108. In some examples, the first retaining surface 112 is planar and extends a substantial length along the body 108 to provide a uniform contact area for securing the test sample. In other examples, the contour of the first retaining surface 112 may correspond to the shape of the test sample, and the first retaining surface 112 enables a non-planar interface. Furthermore, in some examples, the first retaining surface 112 may include a textured feature or coating to enhance grip and reduce slippage of the test sample during securing.

[0043] In some examples, the first retaining surface 112A of the first body 108A is positioned at an oblique angle relative to the first retaining surface 112B of the second body 108B. In other words, the first retaining surfaces have a symmetrical, non-parallel orientation relative to each other. By positioning the retaining surfaces at an oblique angle, the test fixtures 102, 104 constrain the fixed test specimen in a configuration that generates both bending and axial loads when a tensile force is applied to at least one of the load-applying arms, which helps to enable the evaluation of the mechanical response of the test specimen under combined load conditions. In other examples, the first retaining surface 112A of the first body 108A and the first retaining surface 112B of the second body 108B may be perpendicular to each other (e.g., forming a 90° angle relative to each other).

[0044] The body 108 also includes at least one arm attachment opening 110 configured to removably attach a load application arm 120 of the test fixture to the body 108. The arm attachment opening 110 is a through-hole extending through the width of the body 108 at an angle generally parallel to the central plane 122. In some examples, the arm attachment opening 110 may be circular, elliptical, or slotted, depending on the required range of motion of the load application arm 120. The position of the arm attachment opening 110 within the body 108 is configured to allow the load application arm 120 to be attached to a predetermined orientation on the body 108. In some examples, the body 108 includes a plurality of arm attachment openings 110, such that the load application arm 120 can be removably attached to any one of the plurality of arm attachment openings 110.

[0045] See Figure 2The first body 108A of the first test fixture 102 is shown. Similarly, the description of the features of the first body 108A also applies to the second body 108B of the second test fixture 104. The first body 108A includes a plurality of arm attachment openings 110, including a first arm attachment opening 110-1 and a second arm attachment opening 110-2. The first arm attachment opening 110-1 is positioned at a first distance D1 relative to the first holding surface 112A, and the second arm attachment opening 110-2 is positioned at a second distance D2 relative to the first holding surface 112A. As defined herein, the first distance D1 and the second distance D2 are defined as the shortest distance from the center of the respective one of the arm attachment openings 110 to the first holding surface 112A. In some examples, the first distance D1 is different from the second distance D2. Variation in distance from any of the arm attachment openings 110 to the first holding surface 112 provides the ability to adjust the distribution of applied forces within the first body 108A and accordingly affects the generated lever arm. Furthermore, in some examples, the first arm attachment opening 110-1 is positioned at a first height H1 relative to the first top surface 111A, and the second arm attachment opening 110-2 is positioned at a second height H2 relative to the first top surface 111A. As defined herein, the first height H1 and the second height H2 are defined as the shortest distance from the center of the respective arm attachment opening 110 to the first top surface 111A. In some examples, the first height H1 differs from the second height H2. The height difference between H1 and H2 affects the direction and distribution of the applied force through the first body 108A, particularly in terms of how the load path traverses the clamp. In other examples, the first height H1 may be the same as the second height H2.

[0046] Therefore, the selection of the arm attachment opening 110 directly affects the force transmission through the body 108 by changing the lever arm, which influences the balance between bending and axial load distribution. As used herein, the lever arm is defined as the vertical distance from the line of action of the applied force to the center of the radius R of the test specimen. The line of action of the applied force is aligned with the longitudinal axis 126. For example, in Figure 4B In the configuration shown, when the load application arm 120 is fixed to the second arm attachment opening 110-2, the applied force generates a torque around the second arm attachment opening 110-2, which affects the magnitude of the bending moment and axial load (i.e., the combination of the first bending and axial load) generated within the body 108. Conversely, when the load application arm 120 is fixed to the first arm attachment opening 110-1, as... Figure 4CAs shown, the longer lever arm alters the ratio of bending to axial load experienced at the radius (i.e., the combination of the second bending and axial load). The first bending and axial load differ from the second bending and axial load. That is, because the assembly is symmetrical, the applied axial force produces a single bending and axial load in the test specimen. It is worth noting that a particular lever arm length depends on the orientation of the test fixture and the geometry of the test specimen. For more details on the effect of the distance and / or height of the arm attachment opening 110 on the force distribution, refer to the following... Figures 4A-4C Describe it.

[0047] The main body 108 can have any of various shapes. Figure 2 In the example shown, the first body 108A has a generally triangular shape from one side, having a wider upper portion and a tapered lower portion. Viewed from this side, the shape is defined by a perimeter 109A and includes a first top surface 111A, a first inclined surface 113A, and a first retaining surface 112A. When the central plane 122 is parallel to a horizontal line, the second body 108B, as a mirror image of the first body 108A across the central plane 122, has a wider lower portion and a tapered upper portion. In some examples, the first top surface 111A and the first retaining surface 112A are perpendicular to each other, such as in the illustrated example. The upper portion includes arm attachment openings 110-1 and 110-2, which are positioned near the first top surface 111A of the first body 108A, with arm attachment opening 110-1 closer to the first top surface 111A than arm attachment opening 110-2. The first retaining surface 112A extends along one side of the first body 108A, while the opposite side includes a first inclined surface 113A extending from the upper portion to the lower portion.

[0048] Return to reference Figure 1 Each of the first test fixture 102 and the second test fixture 104 further includes a load application arm 120. More specifically, the first test fixture 102 includes a first load application arm 120A, and the second test fixture 104 includes a second load application arm 120B. The load application arm 120 is removably attachable to the body 108 via an arm attachment opening 110. In some examples, the load application arm 120 is secured to the arm attachment opening 110 using a pin 124 extending through the arm attachment opening 110 of the body 108 and an opening (not shown) in the load application arm 20. In other examples, the load application arm 120 is secured by a fastener assembly (e.g., a bolt and nut combination or a quick-release pin) for easy removal and reattachment. In other examples, the load application arm 120 may be attached via a threaded engagement, wherein a threaded fastener may pass through the arm attachment opening 110 and secure the load application arm 20 to the body 108. Figure 2As shown, the first load application arm 120A is secured to the first body 108A by a first pin 124A extending through the second arm attachment opening 110-2.

[0049] In some examples, the load application arm 120 pivots relative to the body 108. By enabling relative pivoting between the load application arm 120 and the body 108, test fixtures 102, 104 can apply both bending and axial forces to the test specimen. Pivoting changes the orientation of the applied force relative to the test specimen, thereby creating a lever arm that generates bending forces in addition to axial tension. The degree or range of pivoting is influenced at least by the selection of the arm attachment opening to which the load application arm 120 is attached. Thus, the pivotability of the load application arm 120 determines how the applied force is transmitted through the corresponding test fixture, and the selection of different arm attachment openings alters the lever arm length, thereby affecting the balance between bending and axial loads. In other examples, the load application arm 120 is fixed relative to the body 108, such that the applied force is transmitted directly to the test specimen through the corresponding test fixture, resulting in minimal or no bending moment.

[0050] In some examples, the load application arm 120 can have any of a variety of shapes and sizes to be compatible with the corresponding test frame, thereby ensuring proper alignment of the force applied from the test frame. Furthermore, the load application arm 120 can be formed from any of a variety of materials, which can be selected based on strength and stiffness requirements, such as high-strength metals that can withstand the applied load without deformation. Additionally, the load application arm 120 can have any of a variety of lengths, wherein the selected length can vary based on the expected load conditions or compatibility with different test frames or load application settings.

[0051] Each of the first test fixture 102 and the second test fixture 104 further includes a back plate 114. Specifically, the first test fixture 102 includes a first back plate 114A, and the second test fixture 104 includes a second back plate 114B. The back plate 114 includes a second holding surface 116, which, together with a first holding surface 112 of the body 108, is configured to hold a test sample therebetween. During testing, the first holding surface 112 and the second holding surface 116 face each other and are spaced apart to define a gap 115, allowing the test sample to be securely positioned between them. Thus, the gap 115 defined between the first holding surface 112 and the second holding surface 116 is configured to receive and hold the test sample. In some examples, the second holding surface 116 is configured to correspond to the first holding surface 112. For example, when the first holding surface 112 is planar, the second holding surface 116 is also planar. In other examples, when the first holding surface 112 is wave-shaped, the second holding surface 116 has a complementary profile with a mirror orientation. In addition, in some examples, the second holding surface may include textured features or coatings to enhance grip and reduce slippage of the test sample when it is held in place.

[0052] The backplate 114 can be removably attached to the body 108 via a fastener 118 extending through a corresponding opening in the backplate 114 and configured to align with a corresponding fastener opening in the body 108. That is, the fastener 118 is configured to removably secure the backplate 114 to the body 108. In some examples, the fastener 118 may be a bolt, screw, or other mechanical fastener that securely attaches to the body 108 while allowing for removal and reattachment. The removability of the backplate 114 facilitates easy placement and removal of the test sample while maintaining a uniformly distributed clamping force to prevent movement of the test sample during testing.

[0053] See Figure 3B The first backplate 114A includes a plurality of first fastener openings 117A. In some examples, the first fastener openings 117A may be arranged in two rows, each row positioned along one of two opposite edges of the first backplate 114A. In other examples, the first fastener openings 117A may be arranged in a single row along the first backplate 114A. In other examples, the first fastener openings 117A may be arranged in different patterns or spacings to accommodate various sample sizes and clamping requirements. The first fastener openings 117A are aligned (not shown) with corresponding fastener openings in the first body 108A so that the first backplate 114A can be secured to the first body 108B at multiple points. The first fastener openings 117A are also configured to align with corresponding openings in the test sample (not shown). Figure 3AAs shown, only the first backplate 114A is shown to better illustrate the fastener 118A extending through the corresponding first fastener opening 117A. In actual use, the fastener 118A will extend through the first fastener opening 117A, through the corresponding opening in the test sample, and engage with the corresponding fastener opening in the first body 108A to secure the first backplate 114A in place.

[0054] Return to reference Figure 1 The first test fixture 102 is configured to move along the longitudinal axis 126 in a first direction perpendicular to the central plane 122 in response to a first applied force F1 applied in a first direction. The second test fixture 104 may move along the longitudinal axis 126 in a second direction opposite to the first direction in response to a second applied force F2 equal in magnitude to the first applied force F1 but applied in a second direction, or remain stationary while the first test fixture 102 moves. Alternatively, the second test fixture 104 may move while the first test fixture 102 remains stationary. The first applied force F1 and the second applied force F2 may be equal and opposite tensile forces, or a force may be applied to one test fixture in one direction while the opposite test fixture remains stationary. The applied forces generate a tensile load on the test specimen fixed to and extending between the test fixtures 102 and 104. This configuration helps ensure that the applied forces remain balanced and uniformly distributed across the specimen, thereby enabling accurate evaluation of the mechanical properties under tensile loads.

[0055] The first test fixture 102 and the second test fixture 104 are configured to be repositioned relative to each other while maintaining a mirror orientation across the central plane 122. This allows the test fixtures 102 and 104 to accommodate test samples of different sizes and / or with features having different radii. In other words, the test fixtures 102 and 104 can be adjusted to account for differences in the width and / or curvature of the test samples while maintaining alignment along the longitudinal axis 126. Maintaining a mirror orientation helps ensure that forces are symmetrically distributed, preventing accidental bending or asymmetrical stress concentration. Furthermore, repositionability improves the versatility of the tension testing tool 100 for controlled applications under different load conditions, while ensuring that the mechanical response of the test sample is evaluated under consistent and repeatable conditions.

[0056] The tension testing tool 100 can be configured for various test settings to evaluate test samples of the same size under different load conditions. Specifically, the first test fixture 102 and the second test fixture 104 can be positioned with various mirror orientations relative to the central plane 122 to achieve controlled variations in force distribution without changing the size of the test sample.

[0057] like Figures 4A-4CAs shown, test specimen 202 is fixed within a tension testing tool 100 for evaluation. Test specimen 202 is a flexural composite structure designed to evaluate interlaminar mechanical properties under controlled loading conditions. Test specimen 202 is a multilayer composite structure consisting of fiber-reinforced polymer layers bonded to a matrix material (e.g., epoxy resin, bismaleimide, or cyanate ester). In some examples, test specimen 202 is tested to analyze interlaminar tension (ILT) strength and failure mechanisms such as delamination and crack propagation.

[0058] Each test specimen 202 has a defined radius R, which affects the distribution of bending and axial forces during testing. The tension testing tool 100 can be configured for use with test specimens of different radii, allowing for the evaluation of curvature-related mechanical behavior across a range of radii. In some examples, the radius R of the test specimen 202 is between 2 and 10 inches, including both 2 and 10 inches, while in other examples, the radius R is between 3 and 7 inches, including both 3 and 7 inches. For example, the test specimen 202 could have a radius R of approximately four inches.

[0059] The test sample 202 includes a first attachment portion 204 and a second attachment portion 206 spaced apart by an intermediate test portion 208. The intermediate test portion 208 has a curved shape defined by a radius R. Specifically, the first attachment portion 204 is secured by a first test fixture 102, while the second attachment portion 206 is secured by a second test fixture 104, which helps ensure that the test sample 202 remains fixed when subjected to load conditions during testing.

[0060] Figures 4A-4C Different configurations of the tension testing tool 100 are illustrated, wherein the positioning of the first test fixture 102 relative to the second test fixture 104 and the orientation of the test sample 202 relative to the tension testing tool 200 vary to achieve different force distributions. While three different configurations are shown, the tension testing tool 100 may have more or fewer configurations than those shown, depending on the number of arm attachment openings 110 in each body 108. In some examples, the tension testing tool 100 is configured in an axially dominant condition (e.g., Figure 4A ), balanced load conditions (e.g.) Figure 4B ) or bending-dominant conditions (e.g.) Figure 4CThe operation of the tension testing tool 100 in at least one of the following configurations is as follows: Axial dominance corresponds to the shortest lever arm configuration, resulting in a higher proportion of axial load relative to bending moment in the force distribution. Balanced load configuration corresponds to an intermediate lever arm length, where both axial load and bending load make significant contributions to the overall force distribution. Bending dominance configuration corresponds to the longest lever arm, resulting in the highest bending moment relative to the axial load. The operation of the tension testing tool 100 in at least one of the axial dominance, balanced load, or bending dominance configurations is based at least in part on the mirror orientation of the first test fixture 102 and the second test fixture 104 relative to each other and a selected arm attachment opening in the arm attachment opening 110 to which the load application arm 120 is attached.

[0061] like Figure 4A As shown, the orientation of the first test fixture 102 and the second test fixture 104 is such that the first holding surfaces 112 of both the first body 102 and the third body 104 are angled inward relative to each other with respect to the central plane 122. The test sample 202 is fixed between the test fixtures 102 and 104, wherein the intermediate test portion 208 is curved outward away from the first holding surface 112. That is, the curvature of the intermediate test portion 208 extends outward, such that the convex side of the test sample 202 faces the inclined surface 113 of the test fixtures 102 and 104.

[0062] The load application arm 120 is attached to the second arm attachment opening 110-2, which is positioned at a greater height from the top surface 111 and a smaller distance from the first holding surface 112 compared to the first arm attachment opening 110-1. Because the vertical distance from the load application axis 126 to the center of radius R is shorter, the resulting lever arm is reduced, leading to a force distribution with a larger proportion of axial load relative to bending moment. The lower height also minimizes rotational effects, thus transmitting force more directly along the longitudinal axis 126 of the tension testing tool 100. Therefore, when tension is applied to at least one of the load application arms 120, the tension generates a larger axial load ratio relative to bending moment, making this configuration an example of an axially dominant condition. This configuration primarily subjectes the test specimen 202 to axial tension while minimizing bending-induced stress, enabling the evaluation of interlaminar tensile strength under the primary axial load.

[0063] Although not shown, the tension testing tool 100 can also be used with the load application arm 120 attached to the first arm attachment opening 110-1, while maintaining the same orientation of the test sample 202. Figure 4AThe overall geometry is shown. In this example, applying a load via 110-1 will cause radius R to close (i.e., induce interlaminar compression) because the line of action passes outside radius R (i.e., on the convex side). While this change may be helpful in studying interlaminar compression behavior, it is not suitable for evaluating interlaminar tension failure modes such as delamination. To induce an opening moment at radius R, the line of action must be on the concave side of radius R (i.e., on the convex side). Figure 4A (As shown on the right) Passing through test sample 202.

[0064] In other examples, the first attachment portion 204 and the second attachment portion 206 may extend in length such that when the first test fixture 102 and the second test fixture 104 are attached to the end of the test sample 202, the fixtures are positioned further apart across the central plane 122. Figure 4A Compared to the previous configuration, this increased spacing causes the radius R to shift further away from the load application axis 126, thereby increasing the vertical distance (i.e., lever arm) from the radius R to the line of action. In this configuration, the applied force generates a larger bending moment, resulting in a more dominant bending condition. Therefore, even with the same attachment orientation (110-2), variations in the geometry of the test specimen can affect whether the applied force produces a more dominant axial or bending response.

[0065] like Figure 4B As shown, the orientation of the first test fixture 102 and the second test fixture 104 is such that the first holding surfaces 112 of both the first body 108A and the second body 108B are angularly positioned outwards from each other relative to the central plane 122. The test sample 202 is fixed between the test fixtures 102 and 104, wherein the intermediate test portion 208 is bent inwards toward the longitudinal axis 126. That is, the curvature of the intermediate test portion 208 extends inwards, such that the concave side of the test sample 202 faces the inclined surface 113 of the test fixtures 102 and 104.

[0066] and Figure 4A Similarly, in Figure 4B In this configuration, the load application arm 120 is also attached to the second arm attachment opening 110-2, positioning the applied force at a greater height from the top surface 111 and a smaller distance from the first holding surface 112. However, due to the outward orientation of the test fixtures 102, 104, the force distribution results in a more balanced combination of bending and axial loads, rather than as... Figure 4AThe dominant axial direction is shown. The tilt of test fixtures 102 and 104 introduces a moderate bending effect, thereby creating a more uniform force state. Therefore, the applied force generates a more balanced distribution between the axial and bending loads, making this configuration an example of a balanced load condition. A balanced load condition does not require that the axial and bending loads be equal, but rather that both the bending and axial components contribute meaningfully to the overall force distribution, rather than one component dominating the response of test specimen 202. This balance ensures the evaluation of interlaminar tensile strength under conditions where both axial tension and bending-induced stress affect the mechanical behavior of the composite structure.

[0067] Figure 4C It shows the relationship with Figure 4B A similar configuration is used, in which the first test fixture 102, the second test fixture 104, and the test sample 202 maintain the same relative orientation. However, in this configuration, the load application arm 120 is attached to the first arm attachment opening 110-1 in each test fixture, and... Figure 4B Compared to the configuration shown, this produces a larger lever arm. Figure 4B In the configuration shown, the load application arm 120 is attached to a second arm attachment opening 110-2, which is positioned at a smaller height from the top surface 111 and a larger distance from the first holding surface 112. Due to the increased lever arm, the applied force generates a higher bending moment relative to the axial load; therefore, this configuration is an example of a bending-dominated load condition. This configuration allows for the introduction of greater bending-induced stress into the test specimen 202 while still maintaining axial tension, thereby enabling the evaluation of interlaminar tensile strength under a bending-dominated load condition. Therefore, by comparison... Figures 4A-4C The response of the test sample 202 can be analyzed to assess how curvature and load conditions affect failure mechanisms such as delamination and crack propagation.

[0068] refer to Figure 5 An example of a tension testing system 200 is shown, wherein a tension testing tool 100 is removably fixed to a test frame 210. As shown, the tension testing tool 100 and the fixed test sample 202 are in a position as follows: Figure 4CThe bending-dominant load state is shown. However, the test frame 210 is adaptable to any configuration of the tension testing tool 100 to achieve controlled evaluation of different force distributions across the fixed test specimen 202. Specifically, the test frame 210 is a structural assembly configured to apply controlled tensile forces to the tension testing tool 100 and the fixed test specimen 202. The test frame 210 includes a load application system 212 configured to control the magnitude and rate of the force applied during testing. The load application system 212 includes an upper crosshead 214, a lower crosshead 216, and a support structure 218 that houses and stabilizes the load components.

[0069] During testing, the first test fixture 102 is removably secured to the upper crosshead 214 of the test frame 210, and the second test fixture 104 is removably secured to the lower crosshead 216 of the test frame 210. The test fixtures 102 and 104 remain spaced apart and maintain a mirror orientation across the central plane 122. In some examples, the upper crosshead 214 moves along the longitudinal axis 126, applying a first applied force F1, while the lower crosshead 216 remains stationary. In other examples, both the upper and lower crossheads 214 move relative to each other, applying a first applied force F1 and a second applied force F2 in opposite directions along the longitudinal axis 126. In still other examples, the lower crosshead 216 moves, while the upper crosshead 214 remains stationary. The support structure 218 maintains the alignment of the tension testing tool 100 within the test frame 210, preventing accidental lateral displacement or misalignment of the test fixtures 102 and 104.

[0070] Each test fixture 102, 104 secures a corresponding holding portion of the test sample 202. Specifically, a first attachment portion 204 of the test sample 202 is removably secured between a first holding surface 112 of the body 108 of the first test fixture 102 and a second holding surface 116 of the back plate 114, while a second attachment portion 206 is similarly secured between the first holding surface 112 of the body 108 of the second test fixture 104 and the second holding surface 116 of the back plate 114. An intermediate test portion 208 extends in the space between the first test fixture 102 and the second test fixture 104.

[0071] In some examples, the test frame 210 is a materials testing system frame, such as a servo-hydraulic, electromechanical, or manually operated tensile testing machine. The load application system 212 may also include force sensors and displacement control mechanisms to facilitate controlled load sequences for evaluating interlaminar tensile strength under various conditions. Furthermore, in some examples, a control system 224 is operatively coupled to the load application system 212 and configured to adjust the load sequence based on real-time measurements. The control system can operate in either displacement control or load control modes while monitoring other parameters to ensure accurate force application. The control system 224 can record the magnitude of the applied force, force distribution, and load response characteristics at various stages of the test, enabling detailed analysis of mechanical behavior, including interlaminar tensile strength and failure mechanisms.

[0072] refer to Figure 7 This illustrates a method 300 for performing a tension test on a test specimen 202. Method 300 includes (block 302) attaching a first load-applying arm 120A to the body 108 of a first test fixture 102 via arm attachment openings 110 in each body 108, and attaching a second load-applying arm 120B to the body 108 of a second test fixture 104. In some examples, the test fixtures 102, 104 may include a plurality of arm attachment openings 110 to allow the load-applying arm 120 to be attached to selected arm attachment openings in the arm attachment openings 110 to adjust the lever arm length and modify the ratio of axial load to bending load applied to the test specimen.

[0073] Each of the arm attachment openings 110 in the first test fixture 102 has a corresponding arm attachment opening in the arm attachment openings 110 in the second test fixture 104 that is mirror-oriented across the central plane 122. A first load application arm 120A is attached to a selected arm attachment opening in the arm attachment opening 110 of the first test fixture 102, and a second load application arm 120B is attached to a corresponding arm attachment opening in the arm attachment opening 110 of the second test fixture 104. The load application arms 120 can be rigidly fixed to the body 108 or pivotally coupled to achieve dynamic force redistribution during testing. In some examples, pins 124 are used to attach the load application arms 120 to the body 108.

[0074] The method also includes (block 304) removably securing the first test fixture 102 and the second test fixture 104 to the test frame 210 such that the first test fixture 102 and the second test fixture 104 are spaced apart across the central plane 122 and mirror each other. The test fixtures 102, 104 can be secured using any of a variety of securing mechanisms, including mechanical clamping devices, hydraulic locking systems, or custom fixture adapters. In some examples, the test frame 210 may include an adjustable mounting position to accommodate different test sample sizes and orientations while maintaining proper alignment during testing.

[0075] The method further includes (block 306) securing a first attachment portion 204 of the test sample 202 between a first retaining surface 112 of the body of the first test fixture 102 and a second retaining surface 116 of the back plate 114 of the first test fixture 102. Additionally, the method includes (block 308) securing a second attachment portion 206 of the test sample 202 between the first retaining surface 112 of the body 108 of the second test fixture 104 and the second retaining surface 116 of the back plate 114 of the second test fixture 104. The first attachment portion 204 is spaced apart from the second attachment portion 206 by a central test portion 208 of the test sample 202. The first retaining surface 112 and the second retaining surface 116 may have texture, coating, or wave-like patterns to enhance grip and minimize slippage. In some examples, the back plate is removably attached to the body using fasteners. The test sample can be secured to the test fixtures 102, 104 in one of an axially dominant condition, a balanced load condition, and a bending dominant condition.

[0076] The method concludes by applying a force (block 310) along the longitudinal axis to at least one of the first load-applying arm 120A and the second load-applying arm 120B to assess the mechanical properties of the test specimen 202. The magnitude and rate of the force can be adjusted to simulate different load conditions. The force can be applied as opposing forces, with each crosshead of the test frame 210 applying equal and opposing forces. Alternatively, a single force can be applied to one crosshead while the other remains stationary. In some examples, the test frame 210 applies a tensile load to the test specimen 202 until structural failure occurs. In some examples, the system can use the test frame 210 to record the failure load and displacement. The collected data is used to calculate bending moments and axial stresses. These results can help generate design values ​​for composite materials and inform predictive strength models for future components, such as composite parts for aerospace applications.

[0077] When force is applied, the response of test sample 202 can be observed to assess its structural integrity. For example... Figure 6A As shown, the test sample 202 is fixed inside the tension testing tool 100 and subjected to forces along the longitudinal axis 126 (see figure). Figure 1 The test specimen is a bent composite structure 220 subjected to tensile force. The first attachment portion 204 and the second attachment portion 206 are clamped between corresponding test fixtures 102, 104, while the intermediate test portion 208 remains exposed to the induced axial and bending loads. During this stage, the test specimen 202 experiences internal stress distribution due to the applied force, but the composite structure remains intact. The interlaminar layers of the test specimen 202 remain fully bonded, and no visible delamination or separation is observed.

[0078] like Figure 6B As shown, after sustained stress, test sample 202 exhibits interlaminar failure, characterized by the separation of at least one of the multiple fiber-reinforced layers of the bent composite structure 220 along an internal plane. The failure region is visible within the intermediate test section 208 where delamination occurs. Specifically, a portion of the material has detached, forming a separation gap 222, indicating a loss of structural integrity between the composite layers. This failure mode indicates interlaminar tension failure, where the applied load exceeds the bond strength between the fiber-reinforced layers, causing the material to crack along its bond layer.

[0079] Therefore, by applying forces in a controlled manner, the system can analyze stress distribution, deformation behavior, and failure mechanisms under combined axial and bending loads. This allows for the capture of stresses from intact composite structures (e.g., Figure 6A ) to interlayer failure (e.g. Figure 6B The ability to transform composite materials provides important insights into the performance and durability of composite materials in real-world applications.

[0080] In the above description, certain terms such as “upper,” “lower,” “upper part,” “lower part,” “horizontal,” “vertical,” “left,” “right,” “above,” “below,” etc., may be used. Where applicable, these terms are used to provide a clear description when dealing with relative relationships. However, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, for an object, simply flipping the object can transform the “upper” surface into the “lower” surface. However, it is still the same object. Furthermore, unless expressly stated otherwise, the terms “including,” “comprising,” “having,” and variations thereof mean “including, but not limited to.” Unless expressly stated otherwise, the list of listed items does not imply that any or all items are mutually exclusive and / or mutually inclusive. Unless expressly stated otherwise, the terms “a,” “an,” and “the” also mean “one or more.” Furthermore, the term “multiple” may be limited to “at least two.” Moreover, unless otherwise stated, as defined herein, multiple specific features do not necessarily mean every specific feature in the entire set or category of specific features.

[0081] In some embodiments, the terms "about" or "substantially" are defined as meaning within + / - 5% of a given value, but in additional embodiments, any disclosure of "about" may be further narrowed and is required to mean within + / - 4%, + / - 3%, + / - 2%, + / - 1%, or the exact given value. Furthermore, when disclosing at least two values ​​of a variable, such disclosure is particularly intended to include a range between those two values, regardless of whether they are disclosed for a separate embodiment or example, and is particularly intended to include at least the smaller of the two values ​​and / or a range not exceeding the larger of the two values. Furthermore, when disclosing at least three values ​​of a variable, such disclosure is particularly intended to include a range between any two values, regardless of whether they are disclosed for a separate embodiment or example, and is particularly intended to include at least value A and / or a range not exceeding value B, where A can be any disclosed value other than the largest disclosed value, and B can be any disclosed value other than the smallest disclosed value.

[0082] Furthermore, instances of one element being "coupled" to another element in this specification can include direct coupling and indirect coupling. Direct coupling can be defined as one element coupling to another element and having some contact with it. Indirect coupling can be defined as two elements not in direct contact with each other, but with coupling between one or more additional elements. Additionally, as used herein, fixing one element to another element can include direct fixing and indirect fixing. Furthermore, as used herein, "adjacent" does not necessarily mean contact. For example, one element may be adjacent to another element without contacting it.

[0083] As used in this article, when used with a list of items, the phrase "at least one of..." means that different combinations of one or more of the listed items can be used, and it may be necessary to use only one of the items in the list. An item can be a specific object, thing, or category. In other words, "at least one of..." means that any combination or number of items from the list can be used, but not all items in the list are required. For example, "at least one of items A, B, and C" could mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, "at least one of items A, B, and C" could mean, for example, but not limited to, two of items A, one of items B, and ten of items C; four of items B and seven of items C; or some other suitable combination.

[0084] Unless otherwise indicated, the terms “first,” “second,” etc., are used merely as labels in this document and are not intended to impose any order, position, or hierarchy on the items referred to by these terms. Furthermore, references to items such as “second” do not require or preclude the existence of items such as “first” or lower-numbered items and / or items such as “third” or higher-numbered items.

[0085] As used herein, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is indeed capable of performing the specified function without any changes, and not merely capable of performing the specified function after further modifications. In other words, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing the specified function. As used herein, "configured to" indicates existing characteristics of the system, apparatus, structure, article, element, component, or hardware that enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modifications. For the purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as "configured to" perform a particular function may additionally or alternatively be described as being "suitable" and / or "operable to" perform that function.

[0086] The schematic flowcharts included in this document are generally illustrated as logical flowcharts. Therefore, the sequence and labeled steps depicted indicate one example of the presented method. Other steps and methods that are functionally, logically, or effectively equivalent to one or more steps or portions thereof of the illustrated method can be envisioned. Furthermore, the format and symbols used are intended to explain the logical steps of the method and should not be construed as limiting the scope of the method. Although various arrow and line types may be used in flowcharts, it should be understood that they do not limit the scope of the corresponding method. In fact, some arrows or other connectors may be used only to indicate the logical flow of the method. For example, an arrow may indicate a wait or monitoring period of unspecified duration between enumeration steps of the depicted method. Moreover, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

[0087] This subject matter may be embodied in other specific forms without departing from its spirit or essential characteristics. The examples described are to be considered illustrative in all respects only, and not restrictive. All changes within the equivalent meaning and scope of the claims should be included within its scope.

Claims

1. A tension testing tool (100), comprising: A first test fixture (102) and a second test fixture (104), each of the first test fixture (102) and the second test fixture (104) comprising: The body (108) includes an arm attachment opening (110) and a first retaining surface (112). Back plate (114), which includes a second retaining surface (116); Fasteners (118) configured to removably secure the backplate (114) to the body (108); and A load-applying arm (120) is removably attached to the arm attachment opening (110) of the body (108). in: When the fastener (118) removably secures the back plate (114) to the body (108), the first retaining surface (112) of the body (108) and the second retaining surface (116) of the back plate (114) are spaced apart and face each other; and The gap (115) defined between the first holding surface (112) and the second holding surface (116) is configured to receive and hold the test sample; The first test fixture (102) and the second test fixture (104) are spaced apart across the central plane (122) and mirror each other.

2. The tension testing tool (100) according to claim 1, wherein, the following At least one of the following: The first test fixture (102) is configured to move along a longitudinal axis (126) in a first direction perpendicular to the central plane (122) in response to a first applied force; and The second test fixture (104) is configured to move along the longitudinal axis (126) in a second direction opposite to the first direction in response to a second applied force equal to the first applied force.

3. The tension testing tool (100) according to claim 1, wherein each of the first test fixture (102) and the second test fixture (104) further comprises a pin (124) configured to extend through the arm attachment opening (110) of the body (108) and an opening in the load application arm (120).

4. The tension testing tool (100) according to claim 1, wherein, For each of the first test fixture (102) and the second test fixture (104), the load application arm (120) is pivotable relative to the body (108) when the load application arm (120) is attached to the arm attachment opening (110) of the body (108).

5. The tension testing tool (100) according to claim 1, wherein each of the first test fixture (102) and the second test fixture (104) includes a plurality of arm attachment openings (110), wherein the arm attachment opening (110) is one of the plurality of arm attachment openings.

6. The tension testing tool (100) according to claim 1, wherein, For each of the first test fixture (102) and the second test fixture (104): The arm attachment opening (110) includes a first arm attachment opening (110-1) and a second arm attachment opening (110-2); and The first arm attachment opening (110-1) is further away from the first retaining surface (112) of the body (108) than the second arm attachment opening (110-2).

7. The tension testing tool (100) according to claim 6, wherein, For at least one of the first test fixture (102) and the second test fixture (104), When the load application arm (120) is attached to the first arm attachment opening (110-1), the force applied to the load application arm (120) is transmitted through the body (108) as a combination of a first bending and axial load. When the load-applying arm (120) is attached to the second arm attachment opening (110-2), the force applied to the load-applying arm (120) is transmitted through the body (108) as a combination of a second bending and axial load; and The first bending and axial load are different from the second bending and axial load.

8. The tension testing tool (100) according to claim 1, wherein the first holding surface (112) of the body (108) of the first test fixture (102) is positioned at an oblique angle relative to the first holding surface (112) of the body (108) of the second test fixture (104).

9. The tension testing tool (100) according to claim 1, wherein the first test fixture (102) and the second test fixture (104) are configured to be repositioned relative to each other while maintaining a mirror orientation across the central plane (122).

10. A tension testing system (200), comprising: A first test fixture (102) and a second test fixture (104), each of the first test fixture (102) and the second test fixture (104) comprising: The body (108) includes an arm attachment opening (110) and a first retaining surface (112). Back plate (114), which includes a second retaining surface (116); Fastener (118) is configured to removably secure the back plate (114) to the body (108). A load-applying arm (120) capable of being removably attached to the arm attachment opening (110) of the body (108); and Test framework (210); During the testing period: The first test fixture (102) and the second test fixture (104) are removably fixed to the test frame (210) such that the first test fixture (102) and the second test fixture (104) are spaced apart across the central plane (122) and mirror each other; The first holding surface (112) of the body (108) of the first test fixture (102) is positioned at an oblique angle relative to the first holding surface (112) of the body (108) of the second test fixture (104); A first attachment portion (204) of the test sample (202) is removably fixed between the first retaining surface (112) of the body (108) of the first test fixture (102) and the second retaining surface (116) of the back plate (114), and a second attachment portion (206) of the test sample (202) is removably fixed between the first retaining surface (112) of the body (108) of the second test fixture (104) and the second retaining surface (116) of the back plate (114), the first attachment portion (204) being spaced apart from the second attachment portion (206) by a middle test portion (208) of the test sample (202); and The test frame (210) applies a force along the longitudinal axis (126) to at least one of the load application arm (120) of the first test fixture (102) and the load force application arm (120) of the second test fixture (104) to evaluate the mechanical properties in the test sample (202).

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