A Numerical Study of the Microscale Plastic Strain Localization in Friction Stir Weld Zones

Abstract

A crystal plasticity approach was used to study the effects of grain shape and texture on the deformation behavior of friction stir weld (FSW) microregions. The explicit stress-strain analysis was performed for two representative grain structures with equiaxed and extended grains. Grain orientations were assigned to simulate no texture or a weak or strong cubic texture. Calculations have shown that the texture gave rise to earlier plastic strain localization on a larger scale. The highest stresses were found to develop in a non-textured specimen with equiaxed grains where the grain boundaries served as a barrier to dislocation motion. In both equiaxed and extended grain structures with a strong cubic texture no pronounced strain localization was seen on the grain scale but mesoscale shear bands appeared early in the deformation process. The calculations have shown that the microstructure-based simulation is a reasonable tool to study the deformation behavior of FSW materials, which is difficult to be predicted within macroscopic models alone.

Choosing the Optimal Multi-Point Iterative Method for the Colebrook Flow Friction Equation

“…This is of a great significance in computing of flow through miscellaneous pipe-networks of various applications (water, natural gas, air, etc. ), in which multiple evaluations of friction factors take place and when certain cases require only rough estimations; while other very accurate computational models need to be compared, repeated, or analyzed in detail [69][70][71].…”

Choosing the Optimal Multi-Point Iterative Method for the Colebrook Flow Friction Equation – Numerical Validation

“…This is of great significance in computing of flow through miscellaneous pipe-networks of various applications (water, natural gas, air, etc.) where multiple evaluation of friction factor takes place and when certain cases requires only rough estimation, while another very accurate scientific computing that need to be compared, repeated or analyzed in details [67][68][69].…”

Measuring strain in sheet metals

“…As a direct consequence of these considerations, the present article has not been implemented with the scope to continue to analyse the behaviour of a telescopic cantilever beam. Instead, it finds the opportunity of the experiment on the telescopic boom, already discussed in [23,31], as a way to investigate the procedures to be adopted for a correct implementation of the experiments [34,35]. As results, numerous practical details and some good tips explain how to apply and use the sensors, suggesting how to pay particular attention not to incur the most common measurement errors.…”