原位四点弯曲测试装置的设计分析与试验研究
发布时间：2019-06-19 14:14
【摘要】：原位力学测试技术是将材料力学性能测试与材料微观变形损伤动态监测相结合的一种新颖的材料测试技术，可以实时观测材料在载荷下的微观结构演变和变形损伤过程，能够为材料力学性能的测试表征以及材料及其制品的优化设计制备提供基础和支撑，对推动材料测试技术的发展具有重要意义。 本文首先综述分析了国内外原位测试尤其是弯曲测试技术的研究进展。原位四点弯曲测试技术在原位力学测试领域方兴未艾，在半导体材料、薄膜材料、生物材料、涂层材料等的力学测试中都发挥了重要的作用。目前的原位弯曲测试多是借助国外商业化的三点/四点弯曲测试仪器，且存在价格昂贵、功能扩展性不强的缺点，而国内对此方面的研究较少，结合此情况，本文研制了一台能够与超景深显微镜等光学显微设备相兼容的原位四点弯曲测试装置，装置总体尺寸200mm105mm66mm，经标定测试所研制装置的载荷量程为500N、分辨率为0.1N，位移量程为10mm、分辨率为1m。论文详细介绍了该测试装置的结构组成与功能原理，并结合理论计算与有限元仿真的方法对装置的关键零部件进行了校核，保证测试装置能够正常工作。 经过测试装置内的传感器标定及初步四点弯曲试验，所研制的原位四点弯曲测试装置能够满足使用要求。针对装置小型化后带来的刚度不足问题，本文对原位四点弯曲装置的机架柔度进行了分析，并利用应变测试法测定了机架柔度系数为C=2.824610-4mm/N。而后，本文提出一种块体材料弹性模量的四点弯曲自动测试法，并利用标定后的原位四点弯曲测试装置测定了6061铝合金、c11000紫铜、微晶玻璃陶瓷、K9光学玻璃四种材料弹性模量，验证了所提方法的可行性。 有限元仿真的方法往往能够发现很多试验难以捕捉到的现象，在近年的力学测试领域发挥着越来越重要的角色。本文采用Abaqus有限元软件模拟了6061铝合金是四点弯曲测试过程，经过与试验得到的载荷-位移曲线对比，保证了仿真的合理性。主要研究了弯曲压头与被测试样的接触误差、压头与试样之间的摩擦、试样不对称放置等因素对四点弯曲测试结果的影响，并且研究了不同跨距比下的材料四点弯曲过程中的应力分布规律，发现应变是决定应力分布均匀性的关键因素之一。 本文利用研发的测试装置开展了7075铝合金V型切口试样在超景深光学显微镜下的原位四点弯曲试验，在线观察了切口附近的裂纹扩展现象，发现切口在压应力区域时相比在拉应力区域材料能够承受更大的载荷，材料的最终失效破坏多是来自于拉应力区域的裂纹累积和扩展。另外，采用四点弯曲测试的方法对c11000紫铜和微晶玻璃陶瓷的预制压痕变形情况进行了研究，，从微观的角度对比了塑性材料和脆性材料的不同。
[Abstract]:In situ mechanical testing technology is a novel material testing technology which combines the mechanical properties of materials with the dynamic monitoring of microscopic deformation damage of materials. It can observe the microstructure evolution and deformation damage process of materials under load in real time. It can provide the basis and support for the testing and characterization of materials and the optimal design and preparation of materials and their products. It is of great significance to promote the development of material testing technology. In this paper, the research progress of in-situ testing, especially bending testing technology at home and abroad is reviewed and analyzed. In situ four-point bending testing technology is in the ascendant in the field of in-situ mechanical testing, and plays an important role in the mechanical testing of semiconductor materials, thin film materials, biomaterials, coating materials and so on. At present, most of the in-situ bending tests are with the help of foreign commercial three-point / four-point bending testing instruments, and have the shortcomings of high price and weak functional expansibility, but the domestic research on this field is less. Combined with this situation, a in-situ four-point bending testing device which can be compatible with optical microscopic equipment such as super-depth of field microscope is developed in this paper. The overall size of the device is 200mm 105 mm 66mm. The load range is 500N, the resolution is 0.1N, the displacement range is 10mm, and the resolution is 1m. In this paper, the structure, composition and function principle of the test device are introduced in detail, and the key parts of the device are checked with the methods of theoretical calculation and finite element simulation to ensure that the test device can work normally. Through the calibration of the sensor in the test device and the preliminary four-point bending test, the in-situ four-point bending test device can meet the requirements. In order to solve the problem of insufficient stiffness caused by miniaturization of the device, the flexibility of the frame of the in-situ four-point bending device is analyzed in this paper, and the flexibility coefficient of the frame is measured to be C 鈮
本文编号：2502405
[Abstract]:In situ mechanical testing technology is a novel material testing technology which combines the mechanical properties of materials with the dynamic monitoring of microscopic deformation damage of materials. It can observe the microstructure evolution and deformation damage process of materials under load in real time. It can provide the basis and support for the testing and characterization of materials and the optimal design and preparation of materials and their products. It is of great significance to promote the development of material testing technology. In this paper, the research progress of in-situ testing, especially bending testing technology at home and abroad is reviewed and analyzed. In situ four-point bending testing technology is in the ascendant in the field of in-situ mechanical testing, and plays an important role in the mechanical testing of semiconductor materials, thin film materials, biomaterials, coating materials and so on. At present, most of the in-situ bending tests are with the help of foreign commercial three-point / four-point bending testing instruments, and have the shortcomings of high price and weak functional expansibility, but the domestic research on this field is less. Combined with this situation, a in-situ four-point bending testing device which can be compatible with optical microscopic equipment such as super-depth of field microscope is developed in this paper. The overall size of the device is 200mm 105 mm 66mm. The load range is 500N, the resolution is 0.1N, the displacement range is 10mm, and the resolution is 1m. In this paper, the structure, composition and function principle of the test device are introduced in detail, and the key parts of the device are checked with the methods of theoretical calculation and finite element simulation to ensure that the test device can work normally. Through the calibration of the sensor in the test device and the preliminary four-point bending test, the in-situ four-point bending test device can meet the requirements. In order to solve the problem of insufficient stiffness caused by miniaturization of the device, the flexibility of the frame of the in-situ four-point bending device is analyzed in this paper, and the flexibility coefficient of the frame is measured to be C 鈮
本文编号：2502405
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