Static And Dynamic Analysis Of Plane Trusses With Damage

With the development of social science and technology, there are more and more various large construction and engineering structures. Because the truss structure is only under axial force, the stress of bar section is uniformly distributed and can also achieve the allowable value, the material of bar can be fully utilized. Compared with the same span beam truss has the advantages of saving material, light weight and other advantages, therefore, the truss structure is widely used in engineering. However, these large engineering structures serving in complicated environment, is not only under all kinds of the design load, but also is affected by various external factors such as sudden natural disasters, earthquake, flood and typhoon and all those make the structural safety at stake. For these large structures, once there is an injury which led to the collapse of malignant results, it will cause the inestimable losses to the lives and properties of the people. It is very important for disaster prevention, if we can know the force performance and the extent of damage of truss structure in use.In order to accurately grasp the stress performance of truss structure in case of damage,this paper uses the analytic method to study the static and dynamic characteristics of the plane truss structure with damage. Firstly, this paper establishes an equivalent cyclic periodic structure system, and set up the control equation; Secondly, using the U transform method to analyze the static problem of plane truss with injury, and derive the analytic solution for the displacement of each node; then the natural frequencies in free vibration and modes of structure in forced vibration are obtained; And the differences of the analytic expressions of displacement of each node between the structure that a rod damage occurs and the structure which many members damage occurs at the same time are discussed; and comparison and analysis between the cases of damage and no damage is made. Finally, the accuracy of the solution is validated by finite element software.