Experimental Study And Theoretical Analysis On Progressive Collapse Resistance Of Space Grid Structures

Several famous progressive collapses have caused extremely serious losses of life and property, also have sounded the alarm in the engineering. It has become an important and realistic topic how to effectively ensure that structures and components have sufficient capacity of resistance to progressive collapse under effects of accidental loads. Until now, the theory and research of progressive collapse focus on the frame structures, but rarely study the progressive collapse of space grid structure, let alone experimental study in this area.The paper designed and made a square pyramidal grid structure, which span was 1.25m, reseau was 5×5 and height was 0.175m, observed the changes of force in the rest of structure and the whole process of progressive collapse under the ventral bar located at the supports failure. The main contents are as follows:(1) The experimental methods of progressive collapse of space grid structures were discussed in order to find a experimental method which can be more comprehensively and more accurately feflect the progressive collapse of space grid structures.(2) Expermental study the performance of progressive collapse of space grid structures. A orthogonal pyramidal grid structure was designed and made in order to observe the changes of force in the rest of structure and the whole process of progressive collapse under the ventral bar located at the supports failure.(3) In order to analyze the characteristic of the the progressive collapse of space grid structures, we analyze the load-strain curve, the load-displacement curve, structure damage mechanism and so on.(4) Simulate the experiment case by software ansys to verify the experiment results. Judge the key elements by the calculations of the compared element, obtain the belly bars and bottom bars located at the supports being the key elements.