多辊矫直过程中H型钢断面的应力演变规律

采用某厂九辊悬臂式变辊距矫直机的工艺参数,建立了H型钢矫直过程的三维动态有限元仿真模型.分析了矫直过程中型钢横截面上的应力分布变化规律,指出其演变特征类似于应力波从翼缘外侧向内侧、翼缘两端向腹板中部的传播过程.仿真结果表明,腹板连接R角以及腹板和矫直辊圆角接触的部位在多辊矫直的后期处于高应力状态,矫后存在明显的应力残余;纵向正应力水平决定矫直效应,而沿纵向的剪切应力会影响H型钢横截面上等效应力的分布.

Stress evolvement rule of an H-beam section during multi-roller straightening process

The 3-D finite element model of an H-beam in straightening process was established by using the processing parameters of a nine-roller cantilever straightener with variable roller spacing.By analyzing the regularity of stress distribution in the H-beam's cross-section during straightening,the character of stress variation was observed which is similar to the stress-wave that spreads from outer-flank to inside-flange,as well as from the two-tips of flange to the middle of web.The simulation result indicates that,the straightening effect is decided by the longitudinal normal stress and the longitudinal shearing stress also affect the distribution of cross-section equivalent stress,while the R corner of web and the area of web contacted with the fillets of straightening rollers suffer from high stress during rear straightening process,and residual stress can also been found after straightening finished.