Determination of the dynamic coefficient by the local damage of the element of steel trusses

Abstract

An important role in the robustness analysis of damaged structures, is played by time during which local damage of the elements of the system occurs. Numerical studies have shown that the shorter the failure time of a particular farm element, the greater the dynamic forces arising in the structure. The time from the beginning of destruction to the complete failure of an element, which consists either in destruction or in loss of stability, is called the time of exclusion. The article describes the results of a series of numerical calculations of steel trusses as part of the building frame with local damage of individual truss elements. The influence of the time of exclusion of the element and the location of its damage on the value of dynamic coefficient was studied. The frame of the building is considered as a space frame, including not only trusses with local damage and the columns on which it relies, but also neighboring trusses, columns, bracing and purlins. This approach allowed to study the effect of local damage on the behavior of intact bearing structures. Based on the calculations, dynamic factors were established for the load acting on the truss with local damage and for the load on adjacent structures of the space frame. Recommendations are offered on constructive measures to increase the robustness of a building with steel trusses. The most unfavorable options for local damage of the trusses have been established. Recommendations are given on the assignment of dynamic coefficient for conducting a static calculation that takes into account the dynamic effects in the building frame with local damage of the truss.