Evolution Characteristics of Uniaxial Compressive Deformation Field of Limestone Based on DSCM Incremental Analysis
Limestone specimens were selected to carry out uniaxial compression tests.Based on the digital speckle correlation method(DSCM),the deformation field was observed,the incremental analysis method was used to calculate the three index increments of non-uniformity index,deformation energy density and deformation field under different stress increments.The evolution characteristics of pre-peak and post-peak stages of rock were studied.The results show that the stress is basically the same when the deformation localization starts in the pre-peak stage,the spatial non-uniformity evolution suddenly increases and the deformation energy density mutation.The nonlinear mutation amplitude of the non-uniformity index increment is proportional to the stress increment step.The larger the stress increment step is,the smaller the mutation starting stress is,while the mutation amplitude of deformation energy density increment is inversely proportional to the stress increment step.The incremental evolution of deformation field under different incremental steps in the post-peak stage is nonlinear fluctuation in the early post-peak stage,and the mutation occurs near the failure.The larger the stress increment step is,the larger the mutation amplitude is.
Digital speckle correlation methodDeformation evolutionUniaxial compressionIncremental analysis
万方数据
维普
