A material testing system configured for load measurement using strain on structural components.

Abstract

Providing material testing systems. [Solution] The illustrated material testing system disclosed comprises a crosshead configured to transmit a test force to a test specimen during material testing; a beam configured to hold the end of the test specimen opposite to the crosshead; an actuator configured to actuate the crosshead and apply a test force to the test specimen; a sensor configured to measure deflection in at least one of the crosshead or the beam; and a control circuit configured to determine the force applied to the test specimen by the crosshead based on the measured deflection.

Description

Technical Field

[0001] [Related Applications] This application claims the benefit of priority of U.S. Patent Application No. 63 / 729,030, filed on Dec. 6, 2024, entitled “MATERIAL TESTING SYSTEMS CONFIGURED FOR LOAD MEASUREMENT USING STRUCTURAL COMPONENT STRAIN”. The entire disclosure of U.S. Patent Application No. 63 / 729,030 is hereby incorporated by reference and made a part of this application (this specification).

[0002] The present disclosure relates generally to material testing systems, and more particularly to material testing systems configured for load measurement using structural component strain.

Background Art

[0003] Material testing machines are used to test the properties (e.g., tensile strength / compressive strength) of various material specimens. Specific test methods (also referred to as test procedures) can vary for each material specimen. Test files can be used to store data related to the test method. Test data, such as the load applied to the specimen being tested, is measured using one or more load cells placed in the load string with the specimen.

[0004] By comparing such systems with the present disclosure described in the remainder of this application with reference to the drawings, the limitations and disadvantages of conventional and traditional approaches will become apparent to those skilled in the art.

Summary of the Invention

[0005] The present disclosure relates to a material testing system configured for load measurement using structural component strain, substantially as illustrated by and / or described with respect to at least one of the figures and more fully set forth in the claims.

[0006] In addition to these and other advantages, aspects, and novel features of this disclosure, the details of the illustrated examples of this disclosure will be better understood from the following description and drawings. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of a materials testing system according to an aspect of the present disclosure.

[0008] [Figure 2] This is a block diagram of the material testing system illustrated in Figure 1, according to an aspect of this disclosure.

[0009] [Figure 3] Figures 1 and 2 show an example of an implementation of a strain sensor coupled to the base beam of the material testing system.

[0010] [Figure 4] Figures 1 and 2 show an example of an implementation of a strain sensor integrated into the base beam of the material testing system.

[0011] [Figure 5A] This figure shows an example strain sensor that can be coupled to the base beam or crosshead in Figures 1 and 2 in order to implement the strain sensor in Figure 3. [Figure 5B] This figure shows an example strain sensor that can be coupled to the base beam or crosshead in Figures 1 and 2 in order to implement the strain sensor in Figure 3.

[0012] [Figure 6] Figures 1 and 2 show an example of an implementation of a strain sensor coupled between the lead screw and the crosshead.

[0013] [Figure 7] Figure 6 shows an example strain sensor that can be used to measure the force applied to a test subject by a crosshead.

[0014] [Figure 8] Figures 1 and 2 show an example of an implementation of a strain sensor coupled between the guide column and the crosshead.

[0015] [Figure 9] This flowchart illustrates one example of a method for performing material testing using strain sensors coupled to or incorporated into the crosshead or base beam of the material testing system, or the lead screws or guide supports of the material testing system, as shown in Figures 1 and 2. [Modes for carrying out the invention]

[0016] The figures are not necessarily on a uniform scale. Where appropriate, the same or similar reference numerals are used in the figures to refer to the same or identical elements. For example, reference numerals with letters (e.g., gripping part 124a, gripping part 124b) refer to the same reference numerals without letters (e.g., gripping part 124).

[0017] A general-purpose material testing system refers to a system that can perform various mechanical tests on a specimen. Examples of tests include tensile strength tests and / or compressive strength tests, torsion tests, shear tests, bending tests, tear tests, peel tests, friction tests, puncture tests, and / or other tests involving mechanical properties. A general-purpose material testing system places the specimen within a "load string," which typically includes the specimen and fixtures that hold the specimen in place during the test. Conventional material testing systems measure the load(s) on the specimen by connecting the load string to an actuator via a load cell and providing measurement signals from the load cell to a monitoring system for calculation of test results. While load cells are accurate and effective for measuring the load on a specimen, including the load cell in the load string necessitates sizing the load cell to the expected load, the load cell may be susceptible to damage due to its exposed position, and the acceptable specimen height for a given general-purpose testing system is reduced.

[0018] The material testing systems described in the disclosures may omit load cells from the load string by measuring the load on the test specimen using measurements of strain, deflection, and / or force in the structural elements of the material testing system. Some disclosed examples involve mounting strain sensors on the surface of a crosshead or base beam supporting the load string and measuring strain or deflection in the crosshead or base beam. In some disclosed examples, the strain sensors may be integrated rather than attached to or mounted on the structural elements (e.g., base beam, crosshead). In yet other disclosed examples, strain, deflection, or force in vertical elements such as lead screws, guide posts, or other support elements is measured to measure the force on the load string.

[0019] The disclosed examples can reduce the number of components required for a material testing system, reduce or eliminate the risk of damage to a load cell that may require costly replacement, and / or increase the range of specimen heights that can be tested in a given material testing system by measuring the strain or deflection in the crosshead and / or base beam and / or the forces on the lead screw and / or guide posts to measure the load on the load string.

[0020] According to aspects of the present disclosure, an exemplary material testing system includes a crosshead configured to be actuated to transmit a test force to a test specimen during material testing, a beam configured to hold an end of the test specimen opposite the crosshead, an actuator configured to actuate the crosshead to apply the test force to the test specimen, a sensor configured to measure deflection in at least one of the crosshead or the beam, and a control circuit configured to determine the force applied to the test specimen by the crosshead based on the measured deflection.

[0021] In some exemplary material testing systems, the sensor is mounted on the crosshead to measure deflection in the crosshead. In some exemplary material testing systems, the sensor is mounted on an outer surface of the crosshead. In some exemplary material testing systems, the sensor is integrated within the crosshead to measure deflection in the crosshead.

[0022] In some exemplary material testing systems, the sensor is mounted on the beam to measure deflection in the beam. In some exemplary material testing systems, the beam is fixed and the crosshead moves relative to the beam. In some exemplary material testing systems, the sensor is configured to measure shear deflection in the crosshead or the beam. In some exemplary material testing systems, the sensor is integrated within the beam to measure deflection in the beam.

[0023] In some exemplary material testing systems, sensors are mounted on the crosshead or beam so as to coincide with the direction of deflection in the crosshead or beam when the crosshead applies force to the test specimen. In some exemplary material testing systems, the control circuit is configured to monitor the force based on the measured deflection and displacement of the crosshead while the force applied to the specimen is being applied to the specimen.

[0024] In some exemplary material testing systems, the sensor includes at least one of a bending strain sensor, a capacitive strain sensor, an encoder-type strain sensor, or an optical strain sensor. In some exemplary material testing systems, the actuator is configured to apply a test force to the test specimen by actinguating a crosshead. In some exemplary material testing systems, the actuator is supported by at least one of a crosshead or a beam and is configured to apply a test force to the test specimen while the crosshead or beam provides a reaction force.

[0025] According to some aspects of the present disclosure, an exemplary material testing system comprises a crosshead configured to be actuated to transmit a test force to a test specimen during material testing; a lead screw coupled to the crosshead and driving the crosshead; an actuator configured to actuate the lead screw and apply a test force to the crosshead; a load cell coupled between the lead screw and the crosshead and configured to measure the force applied to the crosshead by the lead screw; and a control circuit configured to determine the force applied to the test specimen by the crosshead based on the measured force.

[0026] In some exemplary material testing systems, the load cell includes a donut load cell, the donut load cell having a perforation through which a lead screw extends. In some exemplary material testing systems, the load cell comprises a first surface configured to be coupled to a crosshead and a second surface configured to be coupled to a lead screw. In some exemplary material testing systems, the first surface includes the top surface of the load cell. In some exemplary material testing systems, the first surface includes the outer circumferential surface of the load cell. In some exemplary material testing systems, the second surface includes the bottom surface of the load cell, the bottom surface is coupled to a nut driven by a lead screw. In some exemplary material testing systems, the second surface includes an inner circumferential surface coupled to the lead screw via a bearing.

[0027] Some exemplary material testing systems further include a second lead screw coupled to a crosshead and configured to drive the crosshead, and a second load cell coupled between the second lead screw and the crosshead and configured to measure a second force applied to the crosshead by the second lead screw, wherein a control circuit is configured to determine the force applied to the test subject by the crosshead based on the measured second force. In some exemplary material testing systems, the load cell includes a slip ring configured to transmit a measurement signal from the load cell to the control circuit.

[0028] According to some aspects of the present disclosure, an exemplary material testing system comprises a crosshead; a guide column coupled to the crosshead to selectively reinforce the crosshead; an actuator coupled to the crosshead and configured to apply a test force to a load string; a load cell coupled between the guide column and the crosshead and configured to measure the force applied to the guide column by the crosshead; and a control circuit configured to determine the force applied to the test object by the actuator based on the measured force.

[0029] Figure 1 shows an illustrative materials testing system 100. As shown, the materials testing system 100 includes a materials testing machine 102 (also known as a general-purpose testing machine) and a computing system 200 connected to the materials testing machine 102 via a cable 106. The connection is shown as physically connected, but in some examples it may be wireless instead of wired.

[0030] In the example shown in Figure 1, the material testing machine 102 includes a frame 112. In some examples, the frame 112 provides rigid structural support to other components of the material testing machine 102. As shown, the frame 112 includes a top plate 114 and a bottom base beam 116 connected by two support columns 118. In some examples, the support columns 118 of the frame 112 may house guide rails and / or drive shafts 212 of the material testing machine 102 (see, for example, Figure 2). For example, the support columns 118 may include two lead screws having zero, one, or more guide rails, or one lead screw and one or more guide rails.

[0031] In the example in Figure 1, the movable crosshead 120 extends between the support columns 118. In some examples, the movable crosshead 120 may be connected to a guide rail and / or drive shaft 212 housed in the support columns 118 and / or configured to move toward and away from the base beam 116 through the (e.g., motorized) operation of the drive shaft(s) 212. In the example in Figure 1, one movable crosshead 120 is shown, but in some examples, the material testing machine 102 may have multiple movable crossheads 120 and / or other movable members.

[0032] In the example in Figure 1, the fixture 122 is attached to the bottom base beam 116 of the frame 112 and to the movable crosshead 120. As shown, the lower fixture 122a includes a gripping portion 124a, and the upper fixture 122b includes both the test sensor 126 and the gripping portion 124b. In the example in Figure 1, one test sensor 126 and two gripping portions 124 are shown, but in some examples, the material testing machine 102 may include more or fewer test sensors 126 and / or gripping portions 124.

[0033] In the example in Figure 1, the gripping section 124 holds the test subject 128. The test subject 128 is shown as a rope / wire (e.g., made of steel), but in some examples it may be made of some other type of material and / or component. The gripping sections 124a and / or 124b are shown as rope holders, but in some examples they may be configured as bolt holders, wedge grips, side-acting grips, manual grips, roller grips, capstan grips, and / or syringe holders, either as an alternative or in addition thereto. In some examples one or both of the gripping sections 124 may be replaced by a compression platen configured to compress the test subject 128.

[0034] In the example shown in Figure 1, the test sensor 126 is connected to the gripping portion 124 so that it can measure the force acting on the gripping portion 124 (and / or the subject 128, crosshead 120, etc.). In some examples, the test sensor 126 may be a load cell. In some examples, the test sensor 126 may be some other type of sensor.

[0035] In some examples, the material testing machine 102 may be configured for static mechanical testing. For example, the material testing machine 102 may be configured for compressive strength testing, tensile strength testing, shear strength testing, bending strength testing, deflection strength testing, tear strength testing, peel strength testing (e.g., strength of adhesive bonds), torsional strength testing, and / or any other compressive and / or tensile tests. In addition to or alternative to this, the material testing machine 102 may be configured to perform dynamic testing.

[0036] In some examples, the material testing machine 102 is configured to interface with a computing system 200 to carry out a test method. For example, the computing system 200 may communicate with the controller 214 of the material testing machine 102 (see, for example, Figure 2) to carry out a test method.

[0037] Figure 2 is a block diagram showing details of the calculation system 200 and additional details of the material testing machine 102. In the example of Figure 2, the exemplary material testing machine 102 includes one or more actuators 210 connected to one or more drive shafts 212. In some examples, the actuators 210 may be used to provide force to the drive shafts 212 and / or to guide the movement of the drive shafts 212. In some examples, the actuators 210 may include electric motors, pneumatic actuators, hydraulic actuators, piezoelectric actuators, repeaters, and / or switches.

[0038] The drive shaft 212 is further shown connected to the movable crosshead 120 such that the movement of the drive shaft(s) 212 via the actuator(s) 210 results in the movement of the movable crosshead 120. In the example of Figure 2, the term drive shaft 212 is used, but in some examples, the drive shaft 212 may be any other mechanical means that moves the movable crosshead 120 by induction by the actuator(s) 210.

[0039] The exemplary material testing machine 102 further includes a controller 214 that electrically communicates with actuators 210. In some examples, the controller 214 may include a processing circuit and / or a memory circuit. In some examples, the controller 214 may be configured to control the material testing machine 102 based on one or more commands, control inputs, and / or test parameters. In some examples, the controller 214 may be configured to convert commands, control inputs, and / or test parameters (received, for example, from a computing system 200) into appropriate (e.g., electrical) signals that can be delivered to actuators 210, thereby controlling the operation of the material testing machine 102 (e.g., via actuators 210). For example, the controller 214 may provide one or more signals that instruct actuators 210 to provide more or less power, thereby increasing or decreasing the force applied.

[0040] In the example in Figure 2, the controller 214 further communicates electrically with the fixture 122 (e.g., the gripping unit 124 and one or more test sensors 126). In some examples, the controller 214 may be configured to convert commands, control inputs, and / or test parameters (received, for example, from the computing system 200) into appropriate (e.g., electrical) signals that can be delivered to the gripping unit 124, thereby controlling the operation of the gripping unit 124 (e.g., gripping or releasing). In some examples, the controller 214 may be configured to convert commands, control inputs, and / or parameters (received, for example, from the computing system 200) into appropriate (e.g., electrical) signals that can be delivered to one or more sensors 126, thereby controlling the operation of one or more sensors 126. In some examples, the controller 214 may be configured to convert measurement data received from one or more sensors 126 and / or to transmit the measurement data to the computing system 200.

[0041] The exemplary controller 214 further communicates electrically with the control panel 216 of the material testing machine 102. In some examples, the control panel 216 may include one or more input devices (e.g., buttons, switches, slides, knobs, microphones, dials, and / or other electromechanical input devices). In some examples, the control panel 216 may be used by an operator to directly control the material testing machine 102. In some examples, the controller 214 may be configured to control the material testing machine 102 by converting commands, control inputs, and / or test parameters received via the control panel 216 into appropriate (e.g., electrical) signals that can be delivered to the actuator(s) 210 and / or gripping(s) 124.

[0042] The controller 214 is also illustrated as communicating electrically with the network interface 218b of the material testing machine 102. In some examples, the network interface 218b includes hardware, firmware, and / or software for connecting the material testing machine 102 to a complementary workstation network interface 218a of the computing system 200. In some examples, the controller 214 may receive information (e.g., commands) from the computing system 200 through the network interface 218 and / or transmit information (e.g., measurement data from one or more sensors 126) to the computing system 200 through the workstation network interface 218.

[0043] In the example shown in Figure 2, the computing system 200 includes a test workstation 202 and a user interface (UI) 204 interconnected with each other. As shown, the UI 204 may include one or more input devices 206 configured to receive input from the user and one or more output devices 208 configured to provide output to the user.

[0044] In some examples, one or more input devices 206 may include one or more touchscreens, mice, keyboards, buttons, switches, slides, knobs, microphones, dials, and / or other input devices 206. In some examples, one or more output devices 208 may include one or more displays / touchscreens, speakers, lighting, haptic devices, and / or other output devices 208. In some examples, one or more output devices 208 of the UI 204 (e.g., display screens) may output one or more representations of a material testing process 250 configured to enable a user to set up and / or run a test method and / or analyze the test results of a test method. In some examples, one or more input devices 206 of the UI 204 may receive input from a user and send input data representing user input to the test workstation 202.

[0045] In the example in Figure 2, the exemplary test workstation 202 includes a workstation network interface 218a. As shown, one workstation network interface 218a communicates with the network interface 218b of the material tester 102 via cable 106. As shown, the test workstation 202 further includes a workstation network interface 218a that communicates with a network 220 (e.g., the Internet). In the example in Figure 2, the test workstation 202 communicates with a remote interface 230 via network 220 and the workstation network interface 218a. In some examples, the test workstation 202 may communicate with one or more other test systems, servers, and / or other devices via the network and / or workstation network interface(s) 218a. As shown, the workstation network interface 218a is electrically connected to the common electrical bus 222 of the test workstation 202.

[0046] In some examples, the test workstation may be a computing device. In the example in Figure 2, the test workstation 202 includes a workstation processing circuit 224 connected to a common electric bus 222. In some examples, the workstation processing circuit 224 may include one or more processors. In some examples, the workstation processing circuit 224 is configured to process information received from the UI 204, one or more data import devices 108, and / or the material tester 102.

[0047] In some examples, the workstation processing circuit 224 is configured to transmit commands and / or test parameters to the material testing machine 102 (for example, via a network interface(s) 218a). In some examples, the workstation processing circuit 224 is configured to output information to the operator through the UI 204. In some examples, the workstation processing circuit 224 is configured to execute machine-readable instructions stored in the workstation memory circuit 226.

[0048] In the example in Figure 2, the test workstation 202 further includes a workstation memory circuit unit 226 connected to a common electric bus 222. As shown, the workstation memory circuit unit 226 includes a material testing process 250. In some examples, the material testing process 250 includes machine-readable instructions. In some examples, the workstation processing circuit unit 224 is configured to execute the machine-readable instructions of the material testing process 250, communicate with the material testing machine 102 (e.g., the controller 214 of the material testing machine 102), and perform testing of the test subject 128.

[0049] In some examples, the test of test subject 128 is performed according to a specific test method (and / or the test results are analyzed). In some examples, the test method is defined by parameters in a test file. The test file may contain a collection of (e.g., stored) data representing one or more parameters (e.g., test parameters, sample / subject parameters, analytical parameters, etc.) that define at least a part of the test method. For example, the test parameters may include the date the test is performed, test identification information (e.g., number, name, type, description, etc.), target start / end positions of the gripping part(s) 124, target start / end positions of the crosshead 120, target distance / direction moved by the crosshead 120, target speed of the crosshead 120, expected test results(s) (e.g., location / type of breakage, distance moved before breakage, force applied before breakage, post-test characteristics of the sample, etc.), the time(s) at which the sensor(s) 126 should perform the measurement(s) and / or other matters related to the specific test method. The subject parameters may include the date on which the subject 128 was manufactured / shipped / packaged, identification information of the subject 128 (e.g., number, name, description, etc.), pre-test characteristics of the subject 128 (e.g., actual size / dimensions, material type, weight, color, shape, coefficient, maximum tensile strength, etc.), and / or other information relevant to a particular subject 128. The analysis parameters may include one or more algorithms that may be used to evaluate the results of the test method (and / or generate additional test results), one or more test result report formats, and / or one or more thresholds and / or threshold ranges (for example, which can be used to make a ruling on the test result to determine whether the subject 128 passed or failed the test).

[0050] Figure 3 shows an illustrative implementation of a strain sensor 300 coupled to the base beam 116 of the material testing system 100 of Figures 1 and 2. The illustrative strain sensor 300 in Figure 3 is mounted or attached to the base beam 116 to measure the strain and / or deflection of the base beam 116. The illustrative base beam 116 is subjected to strain from the action of forces during material testing. This strain results in a deflection of the base beam 116, which can be measured by the strain sensor 300. In the disclosed example, the deflection and strain measurements are captured at least partially along the length of the base beam 116 or crosshead 120, rather than being captured solely in conjunction with a load string, as in material testing systems using conventional load cells.

[0051] As shown in Figure 3, the strain sensor 300 is mounted on the outer surface of the base beam 116. For example, the strain sensor 300 may be aligned with the direction in which the base beam 116 experiences maximum deflection in order to improve the accuracy and / or precision of the strain measurement. In other examples, the strain sensor 300 is mounted in a different orientation relative to the base beam 116 and / or on another surface of the base beam 116.

[0052] The example strain sensor 300 is mounted on the base beam 116 using standoffs 306. The strain sensor 300 is mounted to these standoffs using screws 304 or other fasteners; however, other mounting methods may be used.

[0053] The processing circuit 224 receives strain measurements or deflection measurements from the strain sensor 300 and calculates the load on the test subject 128 based on these strain measurements or deflection measurements. To improve the accuracy of load measurement, the strain sensor 300 may be calibrated after installation. For example, after the strain sensor 300 is mounted on the base beam 116, one or more loads are applied to the load string, and these loads are measured using load cells. The load measured by the load cells and the deflection measurements measured by the strain sensor 300 are provided to the processing circuit 224, which calculates the relationship between the measured deflection and load present in the load string.

[0054] Figure 4 shows an example implementation of a strain sensor 400 integrated into the base beam 116 of the material testing system 100 of Figures 1 and 2. The strain sensor 400 in the example of Figure 4 may be similar to the strain sensor 300 of Figure 3, except that the body of the strain sensor 400 is configured to be integrated into the body of the base beam 116 (e.g., without fasteners). For example, the body of the strain sensor 400 may be directly coupled to the structure of the base beam 116 so that the deflection of the base beam 116 is directly measured by the strain sensor 400. In some examples, the structure of the base beam 116 includes a surface to which a load cell can be attached to directly measure strain or deflection in the base beam 116.

[0055] The examples in Figures 3 and 4 show strain sensors 300 mounted on or integrated within the base beam 116, but in other examples, the strain sensors 300 may be mounted on or integrated within the crosshead 120 in a manner similar to that shown in Figures 3 or 4 with respect to the base beam 116. For example, the strain sensor 300 may be mounted on the outer surface of the crosshead 120 in a location and orientation that best coincides with the direction of maximum deflection in the crosshead 120 during force application. The strain sensor 400 may be integrated within the structure of the crosshead 120 to directly measure the deflection in the crosshead 120.

[0056] Exemplary sensors that can be used to implement strain sensors 300, 400 include bending strain sensors, capacitive strain sensors, encoder-type strain sensors, optical strain sensors, and / or any other type of strain sensor. Depending on the type of sensor, the orientation of strain sensors 300, 400 relative to the base beam 116 or crosshead 120 may differ in order to align the sensors 300, 400 with the direction of maximum deflection in the base beam 116 or crosshead 120.

[0057] Figure 5A shows an exemplary strain sensor 500 that can be coupled to the base beam 116 or crosshead 120 of Figures 1 and 2 to implement the strain sensors 300 and 400 of Figures 3 and 4. The exemplary strain sensor 500 is an S-shaped strain sensor including ends 502a, 502b and a central section 504. A strain gauge 506 is coupled to the central section 504 (for example, on a beam 508 extending across both ends of the central section 504 between ends 502a and 502b) and outputs a strain signal representing tension or compression on the first end 502a with respect to the other end 502b. This tension or compression causes deformation of the central section 504.

[0058] Figure 5B shows an exemplary strain sensor 550 that can be coupled to the base beam 116 or crosshead 120 of Figures 1 and 2 to mount the strain sensors 300 and 400 of Figures 3 and 4. The exemplary strain sensor 550 is a ring-type strain sensor including a ring section 552 coupled between two end sections 554a and 554b. A strain sensor 556 is mounted to measure the strain in the ring section 552.

[0059] The end sections 554a and 554b are coupled to the base beam 116 or crosshead 120 such that the deflection of the base beam 116 or crosshead 120 pulls the end sections 554a and 554b apart. When the end sections 554a and 554b are pulled apart, the ring section 552 is deformed, and this deformation is measured by the strain sensor 556 and converted into a strain measurement signal. The strain sensor 556 provides the strain measurement signal to the processing circuit 224, which determines the load on the load string as described above.

[0060] In some examples, multiple strain sensors 300, 400 may be mounted or mounted on the base beam 116 or crosshead 120 in different orientations. For example, a first strain sensor 300 may be mounted on the crosshead 120 or base beam 116 in a direction aligned with the direction of maximum deflection for tensile testing, and a second strain sensor 300 may be mounted on the crosshead 120 or base beam 116 in a direction aligned with the direction of maximum deflection for compression testing. Additional strain sensors 300, 400 may be mounted or mounted on the base beam 116 or crosshead 120 to measure deflection under other applied forces.

[0061] Figure 6 shows an example of an implementation of strain sensors 602a and 602b coupled between lead screws 604a and 604b and the crosshead 120 shown in Figures 1 and 2. In the example in Figure 6, strain sensors 602a and 602b are coupled to lead screws 604a and 604b and support the crosshead 120. By driving the crosshead 120 using strain sensors 602a and 602b, the strain sensors 602a and 602b directly measure the force applied to the crosshead 120 by the lead screws 604a and 604b, and as a result measure the force applied to the load string and the test subject 128.

[0062] Figure 7 shows an exemplary strain sensor 700 that can be used to measure the force applied to a test subject by a crosshead, by mounting the strain sensors 602a and 602b of Figure 6. The exemplary strain sensor 700 includes a donut-shaped body 702 having an inner surface 704, an outer surface 706, an upper surface 708, and a lower surface 710.

[0063] The example sensor 700 may be connected to the lead screws 604a and 604b via the inner circumferential surface 704, via a bearing (e.g., a ball bearing). In other examples, the sensor 700 may be supported by the lead screws 604a and 604b, or otherwise connected to the lead screws 604a and 604b via the lower surface 710, such as by being connected to a drive nut connected to the lead screws 604a and 604b.

[0064] The sensor 700 is further coupled to the crosshead 120 via its outer circumferential surface 706 and / or upper surface 708. For example, the outer circumferential surface 706 may be coupled to an annular surface located at the bottom or inside the crosshead 120. In other examples, the bottom or internal surface of the crosshead 120 may be supported by the upper surface 708 of the sensor 700, or coupled to the upper surface 708 in another way.

[0065] The sensor 700 further includes one or more load cells 712 coupled between a) an inner surface 704 and / or lower surface 710 coupled to lead screws 604a and 604b, and b) an outer surface 706 and / or upper surface 708 coupled to the crosshead 120. The load cells 712 monitor the strain and / or deflection between the crosshead 120 and the lead screws 604a and 604b. By including the strain sensor 700 between the crosshead 120 and each of the lead screws 604a and 604b that generate force on the test subject 128, the processing circuit 224 can determine the total load on the test subject.

[0066] To transfer a signal(s) from a load cell(s) 712 to a processing circuit 224, the exemplary sensor 700 may include a slip ring 714 that enables signal transfer when the lead screws 604a, 604b are rotated relative to the sensor 700. The slip ring 714 may be located on any of the inner surface 704, outer surface 706, upper surface 708, and / or lower surface 710, or a combination of surfaces 704-710, and corresponding contacts are provided on the opposing surfaces of the material testing system 100 to relay the signal to the processing circuit 224. In some examples, the raceways of the lead screws 604a, 604b may include slip rings or contacts, and the slip rings in different raceways are electrically isolated. In such examples, the inner surface 704 of the sensor 700 includes opposing contacts or slip rings.

[0067] In yet another example, the sensor 700 may include a wireless communication circuit that communicates a measurement signal or measurement data to a communication circuit (for example, via a communication interface (one or more) 218a).

[0068] In some other examples, one or more lead screws 604 are used to move the crosshead 120 to a desired position, and the crosshead 120 is then clamped in the appropriate position so that an actuator can use the crosshead 120 as a fixed brace beam to apply a test force to the load string. Figure 8 shows an example of an implementation of strain sensors 802a, 802b coupled between guide posts 804a, 804b and the crosshead 120 of Figures 1 and 2. As shown in Figure 8, the crosshead 120 may be clamped, locked, or otherwise fixed to the guide posts 804a, 804b, or another member of posts 118a, 118b to hold the crosshead 120 in a desired position.

[0069] The strain sensors 802a and 802b may be coupled between the crosshead 120 and a post, column, or other structure providing support. The strain sensors 802a and 802b may be implemented in the same or identical manner as the strain sensor 700 in Figure 7, except that, when used, the inner surface 704 may be configured to selectively clamp to the guide columns 804a and 804b instead of sliding on them, or in addition to sliding on them. In other examples, the strain sensors 802a and 802b may be supported (e.g., by their lower surface 710) by locking clamps 806a and 806b, which may selectively clamp to the guide columns 804a and 804b to support the crosshead 120 in a desired position. In such an example, strain sensors 802a and 802b are positioned between the locking clamps 806a and 806b and the crosshead 120 to measure the strain applied to the guide posts 804a and 804b by the crosshead 120.

[0070] To apply force to a load string (e.g., gripping parts 124a, 124b or other fasteners, test subject 128), the material testing system 100 illustrated in Figure 8 includes an actuator 808 coupled to a crosshead 120. The actuator 808 may be positioned on any side of the crosshead 120, as long as it can apply force to the load string relative to the crosshead 120 (e.g., via gripping parts 124a, 124b).

[0071] When actuator 808 applies force to the load string and crosshead 120, strain sensors 802a and 802b measure the force or load between the crosshead 120 and guide posts 804a and 804b and provide the measurement signals to processing circuit 224. The exemplary processing circuit 224 determines the total load applied to the test subject 128 by actuator 808.

[0072] In other examples, strain sensors 300, 500, 550 may be mounted on the crosshead 120, and / or strain sensors 400 may be integrated into the crosshead 120 to measure the deflection of the crosshead 120 when the actuator 808 applies force to the load string.

[0073] Figure 9 is a flowchart illustrating an exemplary method 900 for performing material testing using strain sensors coupled to or incorporated into the crosshead 120 or base beam 116 of the material testing system 100 shown in Figures 1 and 2, or the lead screws 604a, 604b or guide columns 804a, 804b of the material testing system 100.

[0074] In block 902, the operator mounts or attaches one or more strain sensors (e.g., strain sensors 300, 500, 550) to the base beam 116 and / or the crosshead 120, and / or mounts or attaches one or more strain sensors (e.g., strain sensors 602a, 602b, 700, 802a, 802b) to the lead screws 604a, 604b and / or guide columns 804a, 804b of the material testing system 100.

[0075] In block 904, the operator attaches the load cell to the load string and connects the load cell to the processing circuit unit 224 in a communicative manner. For example, the operator may connect the load cell between the crosshead 120 and the gripping unit 124b, or between the base beam 116 and the gripping unit 124a. In another example, the operator may connect the load cell between the gripping units 124a and 124b by gripping the load cell using the gripping units 124a and 124b.

[0076] After the installation of strain sensors (one or more), the material testing system 100 performs a calibration procedure to establish the relationship between the deflection in the base beam 116 or crosshead 120 and the force on the load string.

[0077] In block 906, the processing circuit 224 controls actuators (e.g., actuator 210, actuator 808) to apply a calibration load to the load string. The calibration load may be a predetermined target load, and the processing circuit 224 may store one or more calibration loads applied by actuators 210 and 808. In block 908, the load cell measures the applied calibration load and outputs one or more measured values ​​to the processing circuit 224. In block 910, strain sensors (one or more) 300, 400, 500, 602a, 602b, 700, 802a, 802b also measure strain or deflection in the crosshead 120, base beam 116, lead screws 604a, 604b, or guide columns 804a, 804b, and output strain measured values ​​(one or more) to the processing circuit 224. The processing circuit 224 may receive the measured values ​​(one or more) from the load cell and the strain measured values ​​(one or more) substantially simultaneously, and / or along with timestamps that enable the processing circuit 224 to correlate the measured values. In another example, the calibration load is applied for a predetermined duration so that both the load cell and the strain sensor(s) 300, 400, 500, 602a, 602b, 700, 802a, 802b can establish corresponding measured values ​​for comparison.

[0078] In block 912, the processing circuit 224 determines whether to apply an additional calibration load. For example, the processing circuit 224 may store a set of calibration loads over a desired measurement range of the material testing system 100. In some examples, the calibration loads may extend the desired measurement range upward and / or downward. If an additional calibration load(s) is applied (block 912), in block 914, the processing circuit 224 selects the next calibration load, and control returns to block 906 to apply the next calibration load.

[0079] When no additional calibration loads (one or more) are applied (block 912), in block 916, the processing circuit 224 determines the relationships based on the strain measurements (one or more) and the measured calibration loads (one or more). For example, the processing circuit 224 may perform regression or other curve fitting based on the strain measurements corresponding to the calibration loads measured by the load cell. The processing circuit 224 may store the relationships using algorithms, lookup tables, and / or any other arbitrary format or data. In block 918, the operator removes the load cell from the load string.

[0080] In block 920, the processing circuit 224 determines whether or not to perform a material test. For example, the processing circuit 224 may receive a command from the operator to start a material test (e.g., a tensile test, a compression test, etc.). The command may be received along with the test input and / or test parameters that control the material test. If a material test is performed (block 920), in block 922, the processing circuit 224 controls the actuators 210, 808 to apply a test load to the load string. For example, the actuators 210, 808 may drive lead screws 604a, 604b to apply force to the test subject 128 coupled between the crosshead 120 and the base beam 116.

[0081] In block 924, the processing circuit 224 measures strain or deflection in the crosshead 120 or base beam 116, or force between the crosshead 120 and lead screws 604a, 604b or guide supports 804a, 804b, and outputs the strain measurement values ​​to the processing circuit 224. In block 926, based on the measured strain, deflection, or force and the determined relationship, the processing circuit 224 determines a load profile for material testing. For example, the processing circuit 224 may convert a set (or curve) of strain, deflection, or force measurements into a corresponding set (or curve) of force measurements that represent material testing and / or are equivalent to measurements output by load cells positioned in a load string.

[0082] In block 928, the processing circuit unit 224 outputs the material test results. For example, the processing circuit unit 224 may display a graph of the test force via the user interface 204 (e.g., a display), store the material test results in the memory circuit unit 226, and / or communicate the material test results to one or more external devices via a communication interface (one or more) 218a. After outputting the material test results (block 928), or if the material test is not performed at a specific time (block 920), control returns to block 920 to determine whether or not to perform a material test (i.e., another material test).

[0083] The method and / or system can be implemented in hardware, software, or a combination of hardware and software. The method and / or system can be implemented centrally in at least one computing system, or in a distributed manner in which different elements are distributed across several interconnected computing or cloud systems. Any type of computing system or other device adapted to perform the method described herein is suitable. A typical combination of hardware and software may be a general-purpose computing system with a program or other code that, once loaded and executed, controls the computing system to perform the method described herein. Another typical embodiment may include an application-specific integrated circuit or chip. Some embodiments may include a non-temporary machine-readable (e.g., computer-readable) medium (e.g., flash drive, optical disk, magnetic storage disk, etc.) which stores one or more lines of machine-executable code, thereby causing a machine to perform a process such as that described herein.

[0084] In the context of this application, "and / or" means any one or more items in the list linked by "and / or". For example, "x and / or y" means any element of the set of three elements {(x), (y), (x,y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" means any element of the set of seven elements {(x), (y), (z), (x,y), (x,z), (y,z), (x,y,z)}. In other words, "x, y and / or z" means "one or more of x, y and z".

[0085] As used in this application, the term “for example” commences a list of one or more non-limiting examples, cases, or illustrations.

[0086] As used in this application, the terms "coupled," "coupled to," and "coupled with" mean structural and / or electrical connections, whether mounting, attachment, connection, joining, fastening, linking, and / or other fastening. As used in this application, the term "attach" means to attach, connect, join, fasten, link, and / or other fasten. As used in this application, the term "connect" means to attach, connect, join, fasten, link, and / or other fasten.

[0087] As used in this Application, the terms “circuit” and “circuit section” refer to physical electronic components (i.e., hardware) and any software and / or firmware ("code") that can constitute the hardware, that the hardware can execute, and / or that can otherwise be associated with the hardware. As used in this Application, for example, a particular processor and memory may include a first “circuit” when executing one or more first lines of code, and a second “circuit” when executing one or more second lines of code. As used in this Application, whenever a circuit section includes hardware and / or code (if either is required) necessary to perform a certain function, the circuit section is “operable” and / or “configured” to perform that function, regardless of whether the performance of that function is disabled or not (e.g., by user-configurable settings, factory trim, etc.).

[0088] When used in this application, the control circuit may include digital and / or analog circuitry, discrete and / or integrated circuits, a microprocessor, a DSP, software, hardware and / or firmware, located on one or more boards used to constitute part or all of the controller and / or to control a materials testing system such as a materials testing process and / or a general-purpose materials testing system.

[0089] As used in this application, the term “processor” means a processing unit, device, program, circuit, component, system, and subsystem, whether implemented in hardware, in tangibly embodied software, or both, and whether programmable or not. As used in this application, the term “processor” includes, but is not limited to, one or more computing devices, wired circuits, devices and systems for modifying signals, devices and machines for controlling systems, central processing units, programmable devices and systems, field-programmable gate arrays, application-specific integrated circuits, systems on a chip, systems comprising individual elements and / or circuits, state machines, virtual machines, data processors, processing equipment, and any combination thereof. A processor may be, for example, any type of general-purpose microprocessor or general-purpose microcontroller, a digital signal processing (DSP) processor, an application-specific integrated circuit (ASIC), a graphics processing unit (GPU), a reduced instruction set computer (RISC) processor with an advanced RISC machine (ARM) core, etc. A processor may be coupled to and / or integrated into a memory device.

[0090] As used in this application, the terms “memory” and / or “memory device” mean computer hardware or circuitry that stores information for use by a processor and / or other digital device. Memory and / or memory device may be any suitable type of computer memory or any other type of electronic storage medium, such as read-only memory (ROM), random access memory (RAM), cache memory, compact disk read-only memory (CDROM), electro-optical memory, magneto-optical memory, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), computer-readable media, etc. Examples of memory include non-temporary memory, non-temporary processor-readable media, non-temporary computer-readable media, non-volatile memory, dynamic RAM (DRAM), volatile memory, ferroelectric RAM (FRAM®), first-in, first-out (FIFO) memory, last-in, first-out (LIFO) memory, stack memory, non-volatile RAM (NVRAM), static RAM (SRAM), cache, buffer, semiconductor memory, magnetic memory, optical memory, flash memory, flash card, CompactFlash® card, memory card, secure digital memory card, microcard, minicard, expansion card, smart card, memory stick, multimedia card, picture card, flash storage, subscriber identification module (SIM) card, hard drive (HDD), solid state drive (SSD), etc. Memory can be configured to store code, instructions, applications, software, firmware and / or data, and can be external, internal, or both to the processor.

[0091] While the disclosed methods and systems have been described with reference to exemplary embodiments, those skilled in the art will understand that various modifications and substitutions can be made without departing from the scope of the methods and / or systems. In addition, many modifications can be made without departing from the scope of the disclosure to adapt the teachings of the disclosure to specific circumstances or materials. Thus, the disclosed methods and systems are not limited to the specific embodiments disclosed, but the disclosed methods and systems are intended to include all embodiments that fall within the scope of the appended claims. [Configuration 1] A materials testing system, A crosshead configured to operate to transmit test force to the test subject during material testing, A beam configured to hold the end of the test subject opposite to the crosshead, An actuator configured to operate the crosshead and to apply the test force to the test subject, A sensor configured to measure the deflection in at least one of the crosshead or the beam, A control circuit unit configured to determine the force applied to the test subject by the crosshead based on the measured deflection, A materials testing system equipped with the following features. [Configuration 2] The material testing system according to configuration 1, wherein the sensor is mounted on the crosshead to measure the deflection at the crosshead. [Configuration 3] The material testing system according to configuration 2, wherein the sensor is mounted on the outer surface of the crosshead. [Structure 4] The material testing system according to configuration 1, wherein the sensor is integrated into the crosshead to measure the deflection at the crosshead. [Composition 5] The material testing system according to configuration 1, wherein the sensor is mounted on the beam to measure the deflection in the beam. [Composition 6] The material testing system according to configuration 5, wherein the beam is fixed and the crosshead moves relative to the beam. [Composition 7] The material testing system according to configuration 1, wherein the sensor is configured to measure shear deflection in the crosshead or the beam. [Structure 8] The material testing system according to configuration 1, wherein the sensor is integrated into the beam to measure the deflection in the beam. [Composition 9] The material testing system according to configuration 1, wherein the sensor is attached to the crosshead or the beam such that it coincides with the direction of deflection in the crosshead or the beam when the crosshead applies the force to the test subject. [Configuration 10] The material testing system according to configuration 1, wherein the control circuit is configured to monitor the force applied to the test subject based on the measured deflection and displacement of the crosshead while the force is being applied to the test subject. [Composition 11] The material testing system according to configuration 1, wherein the sensor includes at least one of a bending strain sensor, a capacitive strain sensor, an encoder-type strain sensor, or an optical strain sensor. [Composition 12] The material testing system according to configuration 1, wherein the actuator is configured to apply the test force to the test subject by operating the crosshead. [Composition 13] The material testing system according to configuration 1, wherein the actuator is supported by at least one of the crosshead or the beam and is configured to apply the test force to the test subject while the crosshead or the beam provides a reaction force. [Composition 14] A materials testing system, A crosshead configured to operate to transmit test force to the test subject during material testing, A lead screw coupled to the crosshead for driving the crosshead, An actuator configured to operate the lead screw and to apply the test force to the crosshead, A load cell coupled between the lead screw and the crosshead, configured to measure the force applied to the crosshead by the lead screw, A control circuit unit configured to determine the force applied to the test subject by the crosshead based on the measured force, A materials testing system equipped with the following features. [Composition 15] The material testing system according to configuration 14, wherein the load cell includes a donut load cell, and the donut load cell has a perforation that penetrates the donut load cell, through which the lead screw extends. [Composition 16] The material testing system according to configuration 15, wherein the load cell comprises a first surface configured to be coupled to the crosshead and a second surface configured to be coupled to the lead screw. [Composition 17] The material testing system according to configuration 16, wherein the first surface includes the top surface of the load cell. [Composition 18] The material testing system according to configuration 16, wherein the first surface includes the outer circumferential surface of the load cell. [Composition 19] The material testing system according to configuration 16, wherein the second surface includes the bottom surface of the load cell, and the bottom surface is coupled to a nut driven by the lead screw. [Configuration 20] The material testing system according to configuration 16, wherein the second surface includes an inner circumferential surface coupled to the lead screw via a bearing. [Composition 21] Furthermore, A second lead screw coupled to the crosshead, configured to drive the crosshead, A second load cell coupled between the second lead screw and the crosshead, the second load cell configured to measure a second force applied to the crosshead by the second lead screw, Equipped with, The control circuit unit is configured to determine the force applied to the test subject by the crosshead based on the measured second force. The material testing system described in Configuration 14. [Composition 22] The material testing system according to configuration 14, wherein the load cell includes a slip ring configured to transmit a measurement signal from the load cell to the control circuit unit. [Composition 23] A materials testing system, Crosshead and, A guide post connected to the crosshead for selective reinforcement of the crosshead, An actuator coupled to the crosshead, configured to apply a test force to the load string, A load cell coupled between the guide column and the crosshead, configured to measure the force applied to the guide column by the crosshead, A control circuit unit configured to determine the force applied to the load string by the actuator based on the measured force, A materials testing system equipped with the following features.

Claims

1. A materials testing system, A crosshead configured to operate to transmit test force to the test subject during material testing, A beam configured to hold the end of the test subject opposite to the crosshead, An actuator configured to operate the crosshead and to apply the test force to the test subject, A sensor configured to measure the deflection in at least one of the crosshead or the beam, A control circuit unit configured to determine the force applied to the test subject by the crosshead based on the measured deflection, A materials testing system equipped with the following features.

2. The material testing system according to claim 1, wherein the sensor is mounted on the crosshead to measure the deflection at the crosshead.

3. The material testing system according to claim 1, wherein the sensor is integrated into the crosshead to measure the deflection at the crosshead.

4. The material testing system according to claim 1, wherein the sensor is mounted on the beam to measure the deflection in the beam.

5. The material testing system according to claim 4, wherein the beam is fixed and the crosshead moves relative to the beam.

6. The material testing system according to claim 1, wherein the sensor is configured to measure shear deflection in the crosshead or the beam.

7. The material testing system according to claim 1, wherein the sensor is integrated into the beam to measure the deflection in the beam.

8. The material testing system according to claim 1, wherein the sensor is attached to the crosshead or the beam such that it coincides with the direction of deflection in the crosshead or the beam when the crosshead applies the force to the test subject.

9. The material testing system according to claim 1, wherein the control circuit is configured to monitor the force applied to the test subject based on the measured deflection and displacement of the crosshead while the force is being applied to the test subject.

10. The material testing system according to claim 1, wherein the sensor includes at least one of a bending strain sensor, a capacitive strain sensor, an encoder-type strain sensor, or an optical strain sensor.

11. The material testing system according to claim 1, wherein the actuator is configured to apply the test force to the test subject by operating the crosshead.

12. The material testing system according to claim 1, wherein the actuator is supported by at least one of the crosshead or the beam and is configured to apply the test force to the test subject while the crosshead or the beam provides a reaction force.

13. A materials testing system, A crosshead configured to operate to transmit test force to the test subject during material testing, A lead screw coupled to the crosshead for driving the crosshead, An actuator configured to operate the lead screw and to apply the test force to the crosshead, A load cell coupled between the lead screw and the crosshead, configured to measure the force applied to the crosshead by the lead screw, A control circuit unit configured to determine the force applied to the test subject by the crosshead based on the measured force, A materials testing system equipped with the following features.

14. The material testing system according to claim 13, wherein the load cell includes a donut load cell, and the donut load cell has a perforation penetrating the donut load cell, through which the lead screw extends.

15. The material testing system according to claim 14, wherein the load cell comprises a first surface configured to be coupled to the crosshead and a second surface configured to be coupled to the lead screw.

16. The material testing system according to claim 15, wherein the second surface includes the bottom surface of the load cell, and the bottom surface is coupled to a nut driven by the lead screw.

17. The material testing system according to claim 15, wherein the second surface includes an inner circumferential surface coupled to the lead screw via a bearing.

18. Furthermore, A second lead screw coupled to the crosshead, configured to drive the crosshead, A second load cell coupled between the second lead screw and the crosshead, the second load cell configured to measure a second force applied to the crosshead by the second lead screw, Equipped with, The control circuit unit is configured to determine the force applied to the test subject by the crosshead based on the measured second force. The material testing system according to claim 13.

19. The material testing system according to claim 13, wherein the load cell includes a slip ring configured to transmit a measurement signal from the load cell to the control circuit unit.

20. A materials testing system, Crosshead and, A guide post connected to the crosshead for selective reinforcement of the crosshead, An actuator coupled to the crosshead, configured to apply a test force to the load string, A load cell coupled between the guide column and the crosshead, configured to measure the force applied to the guide column by the crosshead, A control circuit unit configured to determine the force applied to the load string by the actuator based on the measured force, A materials testing system equipped with the following features.

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