Stress analysis of bolted cold formed steel strips by FEM

ABSTRACT In this work a finite element model with three dimensional solid elements is established with Ansys 5.4 (CAE) program for the structural performance of bolted connections and bearing failure of high yield strength and low ductility cold- formed steel bolted connections under shear. In our work we used two different material namely G300 which has low strength, high ductility and G550 which has high strength, low ductility. We used M 12 bolt and two different washer size as smaller and larger during our analysis. And also we did our analysis for two different friction coefficient. Non linear material, geometrical and contact analysis is carried out.The failure mode of investigation is the bearing failure of cold formed steel strip around the bolt holes. The predicted bearing resistance and the strain and stress values of the bolted connections compare well with referance test data. It is found that contact stiffness and frictional coefficient between element interfaces, clamping force developed in bolt shanks and stress-strain curves are important parametres for accurate prediction of the load extension curves of the bolt connections. Comparison with the results of the finite element modelling shows that the existing design rules in both BS5950: Part 5[2] and Eurocode 3: Part 1.3^ give unconservative bearing resistances when thick steel are used.