To study the design method of openings on the web of an I-beam, three I-beams with different circular holes were designed using the traditional truss mechanism, and the circular holes were reinforced by ring stirrups. A shear test was performed to study the failure modes of the I-beams and efficiency of the ring stirrups. A new method for establishing the truss mechanism was proposed, which used the windowed evolutionary structural optimization method to calculate the topology optimization solution of the I-beam. From the topology optimization results, the strut-and-tie model (STM) was established, which revealed the stress mechanism of the I-beam. Via the STM, the optimal shape and location for the opening of the I-beam under shear load states were presented. The quantity of reinforcing bars, porosity and ultimate load of the I-beam designed by the STM were, respectively, 0.67, 5.5 and 1.2 times those of the experimental model.

为研究工字梁腹板上开孔的设计方法，采用传统的桁架机构设计了三个不同圆孔的工字梁，圆孔采用环箍筋加固。进行剪切试验以研究工字梁的失效模式和环箍筋的效率。提出了一种新的桁架机构建立方法，该方法采用窗口进化结构优化方法计算工字梁的拓扑优化解。根据拓扑优化结果，建立了拉筋模型（STM），揭示了工字梁的受力机制。通过STM，提出了在剪切载荷状态下工字梁开口的最佳形状和位置。钢筋数量，