Papers by Author: Tao Wang

Abstract: Only a limited number of experimental and analysis reports exist concerning bolted flange connections under bending loading. In order to investigate the complex nonlinear phenomena, three dimensional elasto-plastic finite element analyses are performed. In those analyses, frictional contact model with small sliding option is applied between contacting pair surfaces of all connecting elements. Bolt pretension force is introduced in the initial step of analysis. From this study, the following results are obtainted:1) proposed finite element analysis method can be applicable to estimate complex nonlinear behavior of bolted flange type connections; 2) There is a sharp change in bending stiffness during loading, and lateral slip between two jointed flanges cause the bolt to carry shear load. The design of bolted joints should consider the interaction among cylinders, flanges and bolts.

Abstract: The theoretical value of bolt pre-tightening torque coefficient is typically 0.2 on load boundary condition simulations.A set of measuring setup has been designed in present study.Through direct measurement and electric measurement,a torque coefficient of 0.15 has been measured.The effects of pre-tightening torque coefficient on bolt stress field are studied numerically.Results show that the coefficient has significant effect on bolt stress fields and relatively conservative results will be achieved if a theoretical value of 0.2 is chosen.Studies on stresses around hole-edge and comparisons with test values show that simulated results of and agree well with test data and the relative errors are no more than 15%.