The Analysis Of Weak Beam Steel Moment Frames Under Cyclic Load

It is always considered that steel frames have remarkable aseismatic performance, and been widely used in high buildings. Previous investigations of earthquake disaster indicate that many collapse occurred in the steel frames of the weld, and mostly belongs to brittle fracture. At present, the connection was independently studied in our nation' research, which have remarkable difference to the actual load-bearing circumstances of the steel frames. So the article based on the non-linear finite element method, carried on the systematic analysis and study to the aseismatic performance of 15 steel moment resisting frames with opening on beam web. And put forward some corresponding seismic-resisting design suggestion.The paper applies nonlinear (material and geometry) finite element method to systematically analyze the overall behaviors of Steel Moment Resisting Frame with Opening on Beam Web under cyclic load for the first time. Based on the aseismic design principle "strong column and weak beam", by reasonable reducing the beam web to ensure the plastic hinge far away from the weld which appear on the beam under high seismic load. The author carried on the comprehensive analyze about every steel-moment resisting frame with different diameter and position of the hole different extent of the holes on beam web. It is analysed systematically about the stress distribution of the key section in frame connection the welded zone and the part of the reduced beam, and contrast analysed to each frames' strength, rigidity, ductility and energy dissipation capacity. And the analysis indicates: reducing the beam web can remarkable improve connection stress distribution, the high three-dimensional stress of the weld condition has distinctively improved, and the plastic deformation area of the beam is remarkably enlarged than the standard frame; increases the diameter of the hole could suitably improve the energy dissipation capacity of the frame; the position of the hole have directly influenced the energy dissipation capacity of the frame, the more closer of the hole' position...