受压U肋加劲板局部稳定受力性能数值模拟

为了掌握受压U肋加劲板的局部稳定受力性能，考虑残余应力与初始几何缺陷，建立U肋加劲板局部稳定试验试件的有限元模型，通过考虑不同宽厚比的试验验证该数值模拟方法的正确性；将U肋加劲板及其腹板简化为四边简支板，并通过数值模拟方法验证四边简支板简化模型的正确性。结果表明:采用数值模拟方法计算得到的破坏模态和应力 位移曲线与试验曲线吻合较好，所计入的残余应力和几何缺陷大小是合理的；采用简化的四边简支板模型和试验试件模型计算的应力 位移曲线从开始到峰值吻合较好，在下降段四边简支板模型下降斜率有所增大；在分析受压U肋加劲板受力性能时，可以选用等效四边简支板简化模型分析其局部稳定承载力。

Numerical Simulation of Local Stability Mechanical Behavior of U-rib Stiffened Plate Under Compression

In order to grasp the local stability mechanical behavior of U-rib stiffened plate under compression, considering the residual stress and initial geometric imperfection, the finite element model of U-rib stiffened plate local stability test specimen was established. The correctness of the numerical simulation method was verified by tests considering different width-to-thickness ratios. The U-rib stiffened plate and its web plate were simplified as quadrilateral simply supported plate, and the validity of the simplified model was verified by the numerical simulation method. The results show that the failure modes and load-displacement curves calculated by numerical simulation method agree well with the test results, the calculated residual stress and geometric imperfection are reasonable. The load-displacement curves of the simplified quadrilateral simply supported plate model and the test specimen are in good agreement from the beginning point to the peak, while the descending slope of quadrilateral simply supported plate model increases. Therefore, the equivalent quadrilateral simply supported plate simplified model can be chosen to analyze the local stability mechanical behavior of U-rib stiffened plate under compression.