有限厚度、大压入的球压试验材料力学响应  

Mechanical Response of Material in Spherical Indentation Test with Finite Thickness and Large Depth

作　　者：谈至明[1] 杨康迪 TAN Zhiming;YANG Kangdi(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学道路与交通工程教育部重点实验室

出　　处：《力学季刊》2019年第4期682-689,共8页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(51778479)

摘　　要：近年来,由布氏硬度压痕试验改进而来的球形压入试验逐渐得到普及,尤其是在测量细观尺度的材料弹性模量时.现行球形压入试验方法中的材料弹性模量计算式是建立在小压入及试件为半空间体的假设基础上的,但实际上这二条件均难以满足.本文研究不同压深、不同试件厚度条件下的试件力学响应后发现:1)当半空间体的压入面相对半径α大于0.1时,原小压入假设的偏差显现应予修正;2)对于压力深度,试件相对厚度小于60;对于压力面半径,试件相对厚度小于6时,应考虑试件厚度的影响,也就是说在测量精度相同条件下,利用压入面半径反演材料弹性模量较利用压入深度进行反演对试件厚度要求较低;对此,总结了小压入假设、试件厚度不足引起的偏差规律,给出了回归修正式;最后还讨论了不同试件厚度对布氏硬度试验的影响.In recent years,the spherical indentation test,which is developed from the Brinell hardness indentation test,is becoming more and more popular,especially when measuring the elastic modulus of materials at mesoscale.The current formula for calculating the elastic modulus of materials in spherical indentation test is based on the assumption that the specimen is semi-infinite and the indentation is small,but in fact these two conditions are difficult to meet.In this paper,the mechanical responses of specimens with different depth and thickness are studied.It shows that:1)When the relative radius of the indentation surface of semi-infinite body is larger than 0.1,the deviation based on the original small indentation hypothesis should be corrected.2)the influence of the thickness of the specimen should be considered when the relative thickness of the specimen regarding to the indentation depth is less than 60,or the relative thickness of the specimen regarding to the indentation area radius is less than 6.In other words,the thickness requirement of the specimen in deriving the elastic modulus of the material by using the radius of the indentation surface is lower than by using the indentation depth under the same measurement accuracy.In this regard,the deviation caused by the hypothesis of small indentation and the insufficient specimen thickness are summarized,and the regression correction formula is given.Finally,the influence of different specimen thickness on Brinell hardness test is discussed.

关 键 词：球形压入 弹性模量 荷载分布形状参数 布氏硬度 材料试验 

分 类 号：TB302.3[一般工业技术—材料科学与工程]