The crack closure is dynamically measured by means of interferometric strain-displacement gauge(ISDG).
用激光干涉应变-位移测量仪（ISDG）进行了裂纹闭合点的高精度动态测量。
2
The load-strain relationship at crack tip is obtained through electric strain gauge measurement.
用电测法得到了裂尖处的载荷—应变标定关系。
3
The initiation time of crack is measured by strain gauge on the sample. The fracture toughness of the composite material is determined by FEM numerical simulation.