Size Effects on Residual Stress Profile and Kres Calculation in 2195 FSW Samples

摘要

Residual stress is the most key factor that affects the application of friction stir weld in aircraft manufacturing. The residual stress profiles were measured in different size samples for notch perpendicular and parallel to weld. Sample size has a big effect on residual stress around notch for both type welds. For notch parallel to weld, sample size didn't change the maximum residual stress so much, while for perpendicular to weld, sample size change it very much, because the maximum residual stress is along the weld direction. Approaches to calculate stress intensity factor from residual stress (Kres) were studied, then weight function were chosen to be used. Kres were compared for three size samples both type welds. Kres starts increasingly from negative to positive, try to follow the tendency of residual stress, but slower than it. For notch perpendicular to weld, Kres keeps the same in the weld zone. More analysis still are ongoing, more results will come soon.