Abstract: In this paper, the developed Moiré technique for assessing high-temperature welding thermal strain is used to study welding thermal strain cycles of aluminum alloy plate with central depositing weld. The images of Moiré fringe of welding kinetic thermal strain field of aluminum alloy have been obtained from the Moiré experiment, and the data been analyzed by data processing method specially developed for the study of Moiré picture of welding thermal strains. It has been studied in the paper the characteristics of welding thermal cycles of aluminum alloy with moving heat sources, which laid a foundation for further research of various mechanical phenomenon during welding and provided reliable data for establishing the data base of welding thermal strains of materials.

Key words: 焊接力学, 铝合金, 热应变, 云纹测试技术