Recent application of caustics on experimental dynamic fracture studies

Abstract

A B S T R A C T Combining the caustic method with high-speed photography is an efficient optical measurement technique to study the dynamic fracture behaviours of homogenous and isotropic material. In the last decade, the main emphasis is extended to study dynamic fracture of anisotropic material and dynamic propagation of multi-cracks and interface cracks in practical engineering materials. In this paper, the recent advances and applications about the dynamic caustic method in China are reviewed, such as impact response and dynamic fracture of composite materials (fibre composites, functionally gradient materials and nanometre composites), and dynamic interaction and propagation of multicracks and interface cracks. Particularly, some new numerical methods were developed to solve the complicated caustic equations by introducing both the maximum characteristic size and the relevant angles in caustic patterns. Also, some important experimental results in fracture mechanics are described, and the potential research prospects about dynamic caustics are included as well.

Three‐dimensional stress fields due to notches in plates under linear elastic and elastic–plastic conditions

“…The caustics have been successfully applied to determine the stress intensity factor of cracks under mode I loading as well as the triaxial state of stresses near the crack tip. That method has been also used to study the dynamic fracture behaviours of homogenous and isotropic material …”

“…That method has been also used to study the dynamic fracture behaviours of homogenous and isotropic material. 32 Recently, displacement image correlation technique has been strongly improved, and it could be used to detect out-of-plane displacements. 33,34 A recent work deals with the measurement of diametral contraction in round tensile specimens made of anisotropic materials.…”

Experimental Investigation of Dynamic Fracture Behaviors of Polymethyl Methacrylate

“…The method of caustics is now recognized as an effective technique to study the stress field around the crack tip for different loading conditions. [22,23] In this method, data, which are used for calculating SIFs, are collected only in the tiny area around the crack tip and there is no need for any information pertaining to the applied force or boundary conditions. In addition, the calculation process is easier than that of any other optical method.…”

Normal impact behaviour of C/SiC rigid‐felt titanium alloy three‐layered plate

“…[3][4][5][6][7][8][9][10][11][12][13] Casavola et al 4 investigated the impact behaviour of sandwich panel by means of both impact experiments and finite element simulations. [3][4][5][6][7][8][9][10][11][12][13] Casavola et al 4 investigated the impact behaviour of sandwich panel by means of both impact experiments and finite element simulations.…”

“…Many works about mechanical behaviour of multilayered plate under impact load have been studied. [3][4][5][6][7][8][9][10][11][12][13] Casavola et al 4 investigated the impact behaviour of sandwich panel by means of both impact experiments and finite element simulations. Cortes et al 5 studied the penetration of ceramic targets backed by thin metallic plates using two-dimensional axisymmetric numerical analysis.…”