连续梁顶板压溃修复过程局部应力分析

综合利用ANSYS软件的"单元生死"及多步求解技术,建立精细化实体有限元模型,分析了某连续梁顶板拆除及修复过程中局部应力分布及变化规律。得出:顶板拆除后,剩余顶板纵横向应力普遍增加3 MPa左右,局部角点出现应力集中;顶板修复及加强后,由于二期恒载及活载的作用,老混凝土纵向应力会继续增加,而横向应力基本不会发生变化。在承受二期恒载及活载前后,最大主压应力及最大主拉应力改变不大,但结构局部应力集中点主压应力达到21.7 MPa,应引起注意。

Analysis on Local Stresses of Continuous Girder in Process of Top Slab Being Crushed and Restored

In this study,by comprehensively using the element birth and death technique as well as the multi-step solving technique of ANSYS software,a refined solid finite element model was established, and the local stress distribution and variation were analyzed for a certain continuous girder in the process of its top slab being crushed and restored. The results showed that:( a) after part of crushed top slab were removed,the longitudinal stress and the transverse stress in the rest of the top slab were generally increased by 3 MPa or so,while the phenomenon of stress concentration occurred at the local corner points;( b) after repairing and strengthening the top slab,the longitudinal stress of older concrete continued to increase because of the action of the secondary permanent load and live load,while the transverse stress of older concrete was not changed basically;( c) before and after bearing the secondary permanent load and live load,both the maximum principal compressive stress and maximum tensile stress were little changed,but the maximum principal compressive stress at the stress concentration points of the structure had reached up to 21. 7 MPa,which should be taken into account.