A strain gage method for determination of fracture parameters in bimaterial systems
- 作者：Marur ; Prabhakar R. ; Tippur ; Hareesh V.
- 关键词：Electrical strain gage ; Interface crack ; Bimaterial ; Complex stress intensity factor ; Impact loading
- 刊名：Engineering Fracture Mechanics
- 出版年：1999
- 期刊代码：33_00137944
- 类别：ms
- 出版时间：September, 1999
- 卷：64
- 期：1
- 页码：87-104
- 文件大小：244 K
摘要
A simple technique for complex stress intensity factor (SIF) determination in a bimaterial crack using electrical strain gages is developed. The asymptotic radial and hoop strain equations are used to compute the SIF by linear transformation. The location of the strain gage relative to the crack tip is chosen through parametric study of the asymptotic fields. The need for higher order terms of the series solution to describe the strain distribution at the gage location is discussed, and a correction procedure using higher order terms is introduced. Static and dynamic experiments are conducted on epoxy/glass-filled epoxy bimaterial specimens in three point bend configuration. Under static loading conditions, the complex SIF estimated from the measured strains is in good agreement with the finite element results obtained by extrapolation of crack flank displacements. The applicability of the present method for dynamic loading conditions is demonstrated by conducting impact tests in a drop-tower system and comparing the measured data with dynamic finite element analysis. The measured dynamic SIF-time history matches favorably with the numerical simulation.