2016 Volume 57 Issue 3 Pages 335-343
Some experimental geometry parameters of four-point bending tests, such as span ratio and support radius, obtained from experience, likely lead systematic errors into the final results. In this paper, some typical geometry effects of four-point bending tests for thin sheet are investigated by employing finite element analysis (FEA). In order to assure the reasonability and accuracy of the FEA results, the standard tensile tests and four-point bending tests are carried out by commercial instruments. Based on the simulation results, it is noted that the stress distribution between the inner supports and outer supports is different with the variation of span ratio. The maximum wedging stress is located near the inner supports. According to the study, the optimum value of the span ratio is suggested to be around 1/3 at plastic stage. In addition, the effects of support radius and contact roughness are also discussed to make a beneficial reference for designing four-point bending experiments and devices.