【摘要】 测量应变集中区域的弹塑性变形,对于研究材料损伤或微裂纹的产生,以预防宏观裂纹的产生及扩展具有重要的意义。为给航空发动机轮盘的损伤容限设计研究提供相关材料的力学实验参数,做了两个有限宽中心带孔试件的拉伸试验。试验中,采用单调逐级加、卸载的循环加载方式,并应用自动网格法和数字图像相关技术测量了孔周的全场位移分布。再应用最小二乘法将离散的位移分量拟合成二元多项式函数,求解出拉伸方向的应变分布,并给出孔边应力σ与孔边应变εy的关系曲线。更多还原

【Abstract】 It is very important to measure the elastic and plastic deformation in the strain concentration zone for studying damage or the micro-crack generating and avoiding macro-crack generating and growing in materials. In order to offer experimental mechanical parameters of correlative material for studying damage-limit-esign of the aircraft engine disk, the tensile tests of two limited width specimens with center-ole were performed. In the measuring processes, the periodic loading to the maximum and then unloading to zero with the same increment were carried out step by step and the whole displacement distribution around the hole was calculated by using automated grid method or digital image correlation. The discrete displacement components were fitted into a 2 dimensional polynomial function by using least square method, the strain distribution along the tensile direction was solved and the stress-train relation curve on the side of hole was given.更多还原