In-plane Nonlinear Stability And Design Method Of Elastically Supported Circular Steel Shallow Arches

Arch structure is a very reasonable structure form with elegant shape and good mechanical performance. Steel is an ideal structural material with the advantages of light weight, high strength and good toughness. Combining the advantages of steel material and arch structure, steel arch is widely used in the field of construction engineering. However, this structure also has a lot of problems in design. Arch structure is mainly in compression condition and the steel cross section is small,which cause the stability problem is prominent. In practical engineering, arches are often supported by other structural members, it is impossible to make completely rigid supports, especially for shallow arches, which ratio of rise to span is small,supported stiffness becomes very important in design. It need further research about the influence of supported stiffness on the stability of steel arch.This thesis focuses on in-plane nonlinear stability performance of elastically supported circular steel shallow arch. Firstly, geometric nonlinear buckling theoretical derivation of circular steel shallow arches with horizontal spring supports are carried on. Secondly, elasto-plastic stability bearing capacity and design method of circular steel shallow arches with horizontal spring supports are studied. Finally, elasto-plastic stability bearing capacity and design method of circular steel shallow arches with horizontal and rotational spring supports are studied. The main achievements of this thesis are summarized as follows.(1) The geometric nonlinear buckling analytical solution of the circular steel shallow arch with horizontal spring supports is given. Compared with the finite element analysis results, theoretical derivation is proved right.(2) The change rule of elasto-plastic ultimate load of circular steel shallow arch with horizontal spring supports is summarized and fitting formula of support horizontal displacements are given. The design formula is modified and then the design method is given from two aspects of the design formula and horizontal support displacements.(3) The change rule of elasto-plastic ultimate load of circular steel shallow arch with horizontal and rotational spring supports is summarized and fitting formula of support horizontal displacements are given. The design formula is modified and thenthe design method is given from two aspects of the design formula and horizontal support displacements.