拱脚沉降下3D打印拱的非线性失稳研究

STUDY ON NONLINEAR INSTABILITY OF 3D PRINTING ARCH UNDER SETTLEMENT OF ARCH FOOT

该文以3D打印材料ABS-M30作为试验载体,开展了拱脚沉降下3D打印拱的非线性失稳研究。基于最小势能原理推导了失稳临界荷载的解析表达式,得到了拱脚竖向和水平变位下拱径向位移沿拱轴线的分布图;设计了可控制拱脚沉降的加载系统,试验得到了拱在加载过程中的平衡路径,并通过有限元模拟对解析与试验结果进行了验证;分析了拱脚沉降量、矢跨比和长细比对3D打印拱失稳临界荷载的影响。研究结果表明:非线性失稳临界荷载随着拱脚沉降量的增大而减小;在拱脚沉降量一定的前提下,非线性失稳荷载随着矢跨比的增大而增大,随着长细比的增大而减小,且长细比的影响最为显著。

Presents an investigation on nonlinear instability of 3D printing arch made of 3D printing material ABS-M30 under the settlement of arch foot.Based on the principle of minimum potential energy,the analytical expression of instability critical load is derived,and the distribution of arch radial displacement along the arch axis under vertical and horizontal displacements of arch foot is obtained.The loading system which is capable of controlling the settlement of arch foot is designed.Then the equilibrium path of arch in the loading process is obtained experimentally,which is verified by analytical and finite element simulation.Meanwhile,the influence of rise span ratio and slenderness ratio on the critical load of 3D printing arch is analyzed.The results show that the nonlinear instability load decreases with the increase of arch foot settlement;with a certain arch foot settlement,the nonlinear instability load increases with the increase of rise span ratio,while decreases with the increase of slenderness ratio which has the most significant effect on the nonlinear instability load.