A device for testing a fiber metal hybrid material under bidirectional loading

Abstract

A kind of biaxial loading test device of fiber metal hybrid material belongs to material testing technology and equipment field, by biaxial loading test device, controllable temperature environment device, computer control device and digital image correlation measurement device, each sub-device is realized collaborative control by computer control device.Biaxial loading test device includes four groups of hydraulic drive loading unit and center sample base, realizes the accurate control of biaxial loading ratio;Controllable temperature environment device integrates heating module, heat preservation module and temperature monitoring module, combines infrared thermal imaging to monitor the temperature of sample in real time, and maintains sample temperature field stability by heat preservation module.The utility model has the advantages of simple structure, reliable performance, can accurately control biaxial loading ratio and strain path, and can record the strain distribution change of fiber metal hybrid cross-shaped sample in biaxial loading process under different temperature conditions, provides high-precision data for coupling analysis of macro-mechanical response and microstructure evolution of hybrid material.

Claims

1. A bidirectional loading test device for fiber-metal hybrid materials, characterized in that, The biaxial loading test device for fiber-metal hybrid materials includes a biaxial loading device, a temperature-controlled environment device, a digital image measurement device, and a computer control device. The bidirectional loading test device uses the machine base (12) as the bottom bearing reference, and its center is a cross-shaped sample placement area; the truss (5) stands upright on both sides of the machine base (12) and the truss crossbar is suspended directly above the machine base (12) as an upper component mounting frame; The dual-axis loading device includes four sets of loading units with the same structure. The four sets of loading units are orthogonally fixed to the machine base (12) with the center of the machine base (12) as the origin. The cross-shaped sample is clamped by the clamps (4) at the ends of the four loading units. The temperature controllable environment device includes an insulated box (9), a hot air gun (10), a magnetic support (11), and an infrared thermal imager (6). The insulated box (9) is installed in the central area of ​​the machine (12). The lower box of the insulated box (9) is connected to the machine (12), and the upper box is detachable. The top surface is provided with heat-resistant and light-transmitting glass (8). A cross-shaped sample (13) is provided inside the insulated box (9). The hot air gun (10) is fixed to the truss (5) through the magnetic support (11). The gun nozzle passes through the heat-resistant and light-transmitting glass (8) and is aimed at the cross-shaped sample (13) inside the insulated box (9). The infrared thermal imager (6) is installed below the crossbar of the truss to monitor the temperature of the cross-shaped sample. The digital image measurement device includes a digital image acquisition unit (7), which is symmetrically mounted on both sides of the truss (5), with the optical axis passing through the heat-resistant and light-transmitting glass (8) and aligned with the center of the cross-shaped sample (13); All devices are connected to a computer control unit via data cables to enable collaborative operation.

2. The bidirectional loading test device for fiber-metal hybrid materials according to claim 1, characterized in that, The biaxial loading device is the core mechanical loading unit of the overall testing device, including a hydraulically driven loading unit (1), a clamp extension rod (2), a hydraulic clamp propulsion unit (3), a chuck (4), and a machine base (12), used to achieve high-precision bidirectional load application and loading path control for the cross-shaped sample of fiber-metal hybrid material; specifically: The hydraulic drive loading unit (1), the clamp extension rod (2), the hydraulic clamp propulsion unit (3), and the chuck (4) form a loading unit, with a total of four groups. They are orthogonally symmetrically distributed at 90° with the geometric center of the machine table (12) as the origin. The bottom of the hydraulic drive loading unit (1) in each loading unit is fixedly connected to the machine table (12). The direction facing the center of the machine table (12) is defined as the inner end, and the direction away from it is defined as the outer end. The inner end of the hydraulic drive loading unit (1) is connected to the hydraulic clamp propulsion unit (3) through the clamp extension rod (2). The end of the hydraulic clamp propulsion unit (3) is equipped with the chuck (4). The tail of the chuck (4) is screwed and assembled with one end of the clamp extension rod (2). After screwing, the clamping center surface of the chuck (4) coincides with the geometric center of the machine table (12). The chuck (4) is provided with an adjusting bolt on its side. The clamping gap is corrected by adjusting the bolt to ensure that the geometric axis of the cross-shaped sample is completely coincident with the clamping center axis of the four sets of chucks (4) after clamping. The clamp extension rod (2) is connected to the hydraulic clamp propulsion unit (3) through an internal threaded hole and then locked by a set screw in the middle of the rod.

3. The bidirectional loading test device for fiber-metal hybrid materials according to claim 1, characterized in that, The digital image measurement device includes a digital image acquisition unit (7) and a computer device, which contains two industrial CCD cameras. Each camera is fixed to the crossbars on both sides of the truss (5) through an adjustable gimbal bracket. The two cameras are distributed at a 45° angle with the geometric center of the machine platform (12) as the symmetrical point. The intersection of the optical axes of the two cameras falls precisely in the central test area of ​​the cross-shaped sample, and the optical axis is perpendicular to the surface of the heat-resistant and light-transmitting glass (8). The distance between the camera lens of the digital image acquisition unit (7) and the heat-resistant and light-transmitting glass (8) is 300~400mm, and the optical axis of the lens penetrates the central area of ​​the glass; the glass surface is coated with an anti-reflective film; the two cameras can achieve synchronous image acquisition.

4. The bidirectional loading test device for fiber-metal hybrid materials according to claim 1, characterized in that, The temperature-controlled environment device adopts a three-in-one design of "contact heating - elastic separation - hot air insulation", including a heat-insulating box (9), heat-resistant and light-transmitting glass (8), and a contact heating structure, specifically: The heat insulation box (9) is a hollow box structure made of heat-resistant mica board (15), including an upper box and a lower box. The lower box is fixedly connected to the preset hole in the center area of ​​the machine (12). The upper box is positioned and assembled with the lower box through a pure aluminum positioning piece (19). After the upper and lower boxes are assembled, the center of the box coincides with the geometric center of the machine (12). The heat-resistant and light-transmitting glass (8) is assembled on the top surface of the heat-insulating box (9); The contact heating structure is located inside the lower box and includes a heating plate (14), a heat insulation base plate (17), a spring (16), and a pipeline (18). The heat insulation base plate (17) provides an installation reference for the heating plate (14) and the spring (16). A cross-shaped sample (13) is placed on the heating plate (14) and fixed to the upper part of the heat insulation base plate (17) by the spring (16). In the initial state, it is in surface contact with the bottom of the cross-shaped sample (13). The spring (16) is located between the heat insulation base plate (17) and the heating plate (14) to form a "pre-stretch-elastic reset" connection pair, which provides power for the separation of the heating plate (14) and the cross-shaped sample (13). The pipeline (18) is connected to the heating plate (14) and the computer control device. The heating plate (14) is a silicon carbide ceramic heating plate; the spring (16) is a cylindrical helical compression spring.

5. The bidirectional loading test device for fiber-metal hybrid materials according to claim 1, characterized in that, The heat-resistant and light-transmitting glass (8) is bonded to the upper box body with a high-temperature resistant sealing strip; the gun body of the hot air gun (10) is clamped and fixed by a 360° rotating clamp at the end of the magnetic support (11), and the clamping force of the clamp is controlled by the adjusting bolt; the vertical distance between the lens center of the infrared thermal imager (6) and the geometric center of the machine (12) is such that the lens field of view covers the entire area of ​​the heat insulation box (9) and captures the temperature distribution of the cross-shaped sample (14) in real time.

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