Research of the stress state in the delamination zone of a laminated steel plate

Many factors (the method of manufacturing the material, the number and thickness of the layers, the pattern of alternating layers) influence on forming and destruction of multilayer materials. The purpose of the work is to evaluate the effect of the thickness of the torn part on the total thickness of the sample on the stress-strain state at the interlayer boundaries of a layered metal composite material based on 09G2S and 12Kh18N10T steels. The debonding process is implemented using finite element modeling in conjunction with the virtual crack closure (VCCT) method. A series of computational experiments has been implemented with varying the critical rate of elastic energy release under conditions of separation of two samples with different ratios of the thickness of the torn part to the total thickness of the sample. As a result of a series of computational experiments, the stress state along the junction boundary was determined. The stratification will begin when the criterion for the critical rate of release of elastic energy GIS is below 40 kJ/m2. The stratification begins to form in different places, depending on the ratio of the thickness of the torn part to the total thickness of the samples under study. The deviation of the maximum main stress at the crack tip from the direction of application of the load is 10°. It is more preferable to use a sample where the ratio of the thickness of the torn part to the total thickness of the sample is less. The results obtained can be used in selecting the geometry of the sample for stratification tests and evaluating the quality of the joint layers.