疲劳试验机加载同轴度偏差的产生与影响  

Generation and Influence of Loading Coaxiality Deviation of Fatigue Testing Machine

作　　者：孙鹏 杨秀光 隋拓 张作良 王洪博 唐士涵 SUN Peng;YANG Xiuguang;SUI Tuo;ZHANG Zuoliang;WANG Hongbo;TANG Shihan(Sinotest Equipment Co.,Ltd.,Changchun 130103,Jilin,China)

机构地区：[1]中机试验装备股份有限公司,吉林长春130103

出　　处：《工程与试验》2025年第1期49-54,60,共7页Engineering and Test

摘　　要：同轴度对疲劳试验机的影响极为显著。本文基于有限元仿真理论,分析在非共线与偏角工况下试样变形与应力变化规律。研究发现,在非共线工况下,试样出现横向挤压现象,试样会向着某个方向发生剪切变形,形成类似于S形的变形,试样表面变形较大一面的应力分布呈现明显的M形,与该应力分布呈面垂直的应力分布呈现扁平的M状态,应力剧烈变化段与最大差值部分集中在试样的根部位置,且随着偏置间距的增加,应力差值与曲线斜率逐渐增大。在偏角工况下,偏角的存在使得加载力可分解为水平与垂直方向的分力,试样呈现出C形的变形,沿试样表面变形较大一面的应力出现两个拐点,随着角度增大而差值增大,与该应力分布呈面垂直的应力分布在试样标距两端的根部出现拐点,且靠近固定端根部的位置应力差值最大,最容易发生断裂。在这两种工况下,截面应力均呈现循环分布的状态。The influence of coaxiality on fatigue testing machine is very significant.Based on the finite element simulation theory,the deformation and stress variation of the specimen under non-collinear and deflection angle conditions are analyzed in the paper.It is found that under non-collinear conditions,the sample has a lateral compression phenomenon,and the sample will undergo shear deformation in a certain direction,forming a deformation similar to the S shape.The stress distribution along the surface of the sample with larger deformation shows an obvious M shape,while the stress distribution perpendicular to the surface presents a flat M state.The section with severe stress changes and the maximum difference is concentrated at the root of the sample,and as the non-collinear distance increases,the stress difference and the slope of the curve gradually increase.Under the condition of deflection angle,the existence of deflection angle makes the loading force be decomposed into horizontal and vertical components,resulting in a deformation of the specimen in a C shape.There are two inflection points in the stress on the surface of the specimen with larger deformation,and the difference increases with the increase of angle.The stress distribution perpendicular to the surface shows inflection point at the root of the specimen at both ends of the gauge length,and the root position near the fixed end has the largest stress difference,which is most prone to fracture.Under these two conditions,the cross-sectional stress shows a cyclic distributed.

关 键 词：疲劳试验机 同轴度 应力 非共线 偏角 有限元分析 

分 类 号：TH87[机械工程—仪器科学与技术]