含局部焊接细节的钢桁架结构静动力响应实验研究

Experimental Research on Static and Dynamic Response of a Steel Truss with Local Welding Details

从考虑损伤的结构有限元模拟的研究需要出发,对考虑焊连接细节构造的钢桁架结构试样进行了结构动力特性及特定载荷下的静力响应实验研究。文中给出了对试样结构进行动力特性测试和结构整体与局部应力分布状态的测试结果及其分析,并将有限元计算的结果与测试结果进行了对比分析。研究结果表明:结构动力特性的计算结果和测试值比较接近,存在的误差主要来自于边界条件的不确定性和可能的材料不均匀性;边界约束的形式对结构名义应力的分布有明显的影响,但对于焊接细节处的热点应力分布的影响很小。实验中所关注部位的热点应力在均布载荷作用下随载荷级别的提高,应力值由下翼缘的中间向两边增大,在焊缝附近有应力突变。

For the purpose of finite element simulation considering the fatigue damage, the experiment on dynamic characteristics and static response of a steel truss specimen with local welding details and under specific loading was carried out. Modal parameters of the test , the structural global stress and the local stress distribution are presented, the comparison between the test values and the calculated ones is also presented in this paper. All results show that the test values of dynamic characteristics are close to the predicted ones, and the resulting errors are probably caused by uncertainties of boundary conditions and possible material unhomogeneousness. The difference of boundary constraint has a distinct influence on the structural nominal stress distribution but only little on the hot-spot stress. The hot-spot stresses of concerned locations are getting higher with the incremental uniformly- distributed loading level, and stress value increase from the middle of bottom flange to the both sides. Stress singularity phenomenon was found around the welding.