陈建云,陆大敏,莫德凯,匡正,张克实,常岩军*.对称拉压循环对HRB400E钢弹塑性行为影响的试验研究[J].实验力学,2019,34(5):759~766 |
对称拉压循环对HRB400E钢弹塑性行为影响的试验研究 |
Experimental study on elastoplastic behavior of HRB400E steel under low-cycle symmetric loading |
投稿时间:2019-01-19 修订日期:2019-03-22 |
DOI:10.7520/1001-4888-19-016 |
中文关键词: 预循环 HRB400E钢 硬化行为 滞回曲线 塑性功 断口 |
英文关键词:pre-cycle HRB400E steel hardening behavior hysteretic curve plastic work fracture surface |
基金项目:国家自然科学基金项目(11472085,11632007),广西重点实验室系统性研究项目资助(2016ZDX07), 广西教育厅项目(2019KY0003) |
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中文摘要: |
对HRB400E钢在单向拉伸、拉压循环和循环后拉伸载荷作用下的力学行为进行了试验研究,采用0.3%、0.4%、0.5%、0.6%、0.7%、0.8%、0.9%和1%八种对称应变幅对HRB400E薄壁圆管试件施加100周次拉压循环载荷,循环后施加单轴拉伸载荷直至试件断裂。试验数据分析表明,循环加载过程中HRB400E钢前10周应力应变曲线曲率明显变小,峰值应力明显下降,呈现循环软化特性,随着应变循环幅值的增大,循环滞回曲线稳定所需循环周次逐渐减小。HRB400E钢在不同应变幅循环后的拉伸弹性模量均出现下降,下降幅度约为3%~8%,屈服应力会随着预循环应变幅的增大而增大,随着预循环应变幅增大材料的硬化效应有所减弱。与单轴拉伸相比,循环后拉伸的强度极限和断裂应变无明显变化,塑性变形能力没有明显下降,破坏为典型的塑性剪切断裂模式,薄壁圆管试件断口中的断裂纤维区和剪切唇区位于接近管壁处,断面径向中部的断裂扩展区中,在大韧窝周围存在多个较小韧窝。 |
英文摘要: |
The mechanical behaviors of HRB400E steel under uniaxial tension, tension and compression cycle and tension after cycle at room temperature were studied. The HRB400E thin wall tube specimens were subjected to 100 cycles load with 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% and 1% tension and compression symmetric cyclic strain amplitudes, and the uniaxial tension test was carried out after cyclic loading. The experimental results show that the curvature of the stress-strain curve of HRB400E steel and the peak stress decreases obviously in the first 10 cycles during cyclic loading, exhibiting the cyclic softening characteristic. The cyclic hysteretic curve stabilizes faster as the cyclic strain amplitude gets larger. The tensile elastic modulus of HRB400E steel decreases about 3%~8% after cyclic loading with different strain amplitudes. The yield stress increases slightly with the increase of pre-cycle strain amplitude. Therefore, the hardening effect based on the strength-yield stress ratio will weaken with the increase of the pre-cycle strain amplitude. Compared with uniaxial tension, there were no significant change in tensile ultimate strength and fracture strain of the tensile after cyclic loading, and the plastic deformation ability does not decrease obviously with the typical plastic shear fracture mode. The fibrous zone and shear lip zone in the tensile fracture surfaces appear near the external surface and internal surface of thin-walled tubular specimens and the propagation zone grows in the center of the fracture surface, in which there are many small dimples around the big dimple. |
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