优化方法建立钢筋混凝土梁压杆-拉杆模型

CONSTRUCTION OF STRUT-AND-TIE MODEL FOR REINFORCED CONCRETE BEAMS BY OPTIMAL METHOD

压杆-拉杆模型是复杂钢筋混凝土结构设计的标准方法之一,但很少扩展到浅梁的设计。钢筋混凝土梁压杆-拉杆模型的建立方法很多,但由这些方法得到的压杆-拉杆模型是否能反映结构最本质的受力状况尚无定论。该文采用寻优能力强的拓扑优化算法——遗传演化结构优化算法(GESO)来构造钢筋混凝土梁的压杆-拉杆模型,同时为了确保所得结果的最优性,采用经典的Michell准则和试验方法判断和解释GESO算法的计算结果。该文以跨高比从7变化到1的简支梁和两跨连续深受弯构件为例证明了采用GESO算法能构造满足Michell准则的钢筋混凝土梁压杆-拉杆模型,由该文总结出的钢筋混凝土梁的压杆-拉杆模型的规律有助于设计类似构件。

Strut-and-tie model method is one of the standard methods for the design of a complex reinforced structure, but it seldom extends to shallow beams. There are many ways for reinforced concrete deep beams to construct a strut-and-tie model, but the strut-and-tie models achieved are not deem to reflect the most essential mechanical state of the beams. One powerful topology optimization named genetic evolutionary structural optimization （GESO） is used to build a strut-and-tie model for reinforced concrete beams in the paper. In order to ensure the results to be optimums, the classical Michell criterion and experiments are used to judge and explain the GESO results. The examples include a series of simply supported beams with span-to-height from 7 to 1, which cover deep beams and shallow beams and two span continuous deep beams with concentrated loads and uniform loads. The examples cited prove the validity of GESO algorithm in building strut-and-tie models for reinforced concrete beams. The laws of strut-and-tie models of the examples are concluded to help the design of similar beams.