Influence of laser-arc hybrid welding conditions on cold cracking generation

For extending application of laser-arc hybrid welding on manufacture and fabrication of large steel structures such as bridges and ships, proper welding conditions should be identified. In order to mechanically evaluate welding cold cracking by laser-arc hybrid welding, a series of experiments and numerical simulation was carried out. A numerical simulation model by finite element analysis for laser-arc hybrid welding was proposed. The validity of the simulation model was verified by comparing the analytical results with the experimental results. It was confirmed that the restraint strain proposed as a measure for cold cracking in arc welding could be applied on the laser-arc hybrid welding. Based on the evaluation measure, the influence of laser-arc hybrid welding conditions on the cold crack occurrence was investigated.