Investigation On Contact Deformation Of Mining Flat Type Chain Connector Based On Digital Image Correlation Method

As a typical multi-tooth bearing structure,the chain connector is widely used in the connection of circular chain of equipment such as mining and shipbuilding.Since the contact deformation distribution is extremely complicated,the analysis of the full field deformation of the chain connector has always been a difficult point of research.In this paper,the segmentation-aided digital image correlation(SA-DIC)method is used to analyze the contact deformation of mining flat type chain connector in the multi-tooth meshing state.The full-field deformation distribution of this structure under tensile load is measured,and the strain concentration phenomenon in the vicinity of contact surface is qualitatively and quantitatively analyzed.The experiment takes ?26mm?92mm standard ladder-toothed chain connector model as the research object,and proposes the corresponding multi-resolution method to measure the contact deformation.In this method,only a single camera is used to implement multi-resolution testing,thereby avoiding image correction errors in the conventional multi-resolution method.The subsampled images are used to calculate the full-field deformation of the specimen so as to achieve efficient strain distribution analysis and position the strain concentration regions.The high-resolution images are used for local deformation calculation to analyze the deformation distribution of the strain concentration regions.The experimental results show that the strain concentration is mainly concentrated in the contact area of the second pair and the third pair of teeth of the chain connector,and the deformation and strain gradient of the areas are much higher than other areas due to the bending stress and the contact stress.In order to explore the influence degree of deformation distribution and strain concentration of different structural parameters on the chain connector,a four-factor and three-level orthogonal test of tooth width and root fillet coefficient was designed.The strain results show that the overall distribution trend of the strain field of different specimens is similar,but the local deformation is still quite different.The maximum principal strain and the maximum shear strain of the chain connector are used as test indicators.The variance analysis is performed on the orthogonal test.The results show that the third tooth has a significant influence on the maximum principal strain,and the first pair of tooth width and the root radius have a significant influence on the maximum shear strain.After comprehensive balance,the optimal horizontal combination that minimizes the deformation of the chain connector is obtained.