Stress and strain analysis of metal plates with holes

摘要

For our long-term goal of understanding how metal connectors used for housing respond to hurricanes' wind load, we have conducted Finite Element Analysis (FEA) to compute the stress and strain distributions in tensile-loaded, aluminum and tin plates with holes. The specimen is 20 - 25 mm wide, 0.1 - 10 mm thick, and 100 mm long in the direction of the tensile axis along which two holes are drilled. In addition, we have conducted tensile experiment using an optical interferometer and analyzed the in-plane strain field. Comparison of the FEA and experiments indicate that band-like interferometric fringe patterns representing strain concentration coincide with the region where the von-Mises yield criterion is satisfied, and that the specimen fractures at the hole that shows more concentrated plastic strain. Experimental results show that in the tin samples the fracture lines run through the hole perpendicularly to the tensile axis, while in the aluminum samples the fracture lines run about 45 degrees to the tensile axis. Results of the corresponding FEA are consistent with this observation, showing that the plastic strain patterns observed in the tin samples are much more horizontal than those in the aluminum samples.