300t履带起重机臂架应力分析与测试

Stress test and analysis of boom for 300t crawler crane

履带起重机臂架是重要的承载构件,变截面处承受轴向载荷和弯矩引起较大应力,在长期使用过程中易存在开裂的可能。为深入了解工作状态中臂架结构实际受力情况和应力分布规律,对300 t履带起重机的标准型主臂进行实车应力测试,获取典型工况下危险截面测点应力值。根据该起重机的常用载荷工况,采用非线性计算方法对不同工况下的起重臂架进行有限元分析,通过对结果分析,确定顶节、标准节、底节附近的3个危险截面,汇总各工况下3个危险截面上4根弦杆的最大应力,分析应力分布变化趋势。由此确定测点布置,并根据规范,制定臂架应力测试的试验方案,通过获得的静态和动态测试的应力数据,与有限元结果对比,表明了有限元模型的有效性。

The boom of crawler crane is an important load-bearing structure. The variable crosssection of boom bears large stress caused by axial load and bending moment,which may crack during long-term use. In order to deeply understand the actual stress situation and stress distribution of the boom structure in the working cases,the real stress test is carried out to obtain the stress of the dangerous cross-sections under the typical working condition. According to the common load conditions of the crane,the FEM of the boom is built and analyzed with nonlinear method. Three most dangerous cross-sections are determined among the top section,standard section and bottom section of the boom respectively. The maximum stress of four chords on these cross-sections under each working case is summarized,and the change trend of stress distribution is analyzed. Therefore,the test points are determined. According to the specification,the test scheme of boom stress is planned,and the stress test data of these cross-sections of static and dynamic test are obtained. The FEA results are compared with the test ones,and the effectiveness of the finite element model is verified.