Strength evaluation of bolted connections with slotted holes in non‐structural components

Abstract

ABSTRACTIn the bolted connections of the non‐structural exterior wall to structural frames, slotted holes are often used to improve the workability. In Japan, in case the slotted holes are used in the bolted connections of structural frame, a reduction factors according to European Recommendations for bolted connections in structural steel work(1) have to be employed to reduce the slip strength of the connections. However, the strength reduction ratio equals to 1.0 when the major axis direction and the stress direction of the slotted holes are orthogonal; thus, the strength reduction factor is not considered to be substantial in many cases. Furthermore, these provisions are not employed for connections of non‐structural components to structural frames.In this study, a tension test of bolted connection with slotted hole was carried out to evaluate the slip coefficient and confirm the strength reduction. In order to consider influences of the surface treatment of the specimen on slip proof stress, five different types of surface treatment are considered in the test, which are hot dip galvanizing with and without antirust processing, electroplated zinc colored chromate coating with and without antirust coating, and stainless steel. From the test results, it is found that the slip strength ratio of the bolted connection with the slotted holes to that of with the conventional holes was ranging from 0.70 to 0.80. As next step, a series of slip coefficient evaluation experiments of actual non‐structural components are planned to investigate that the reduction factor obtained from the element tests could be adopted to the components. In that case, eccentricity and stress distribution in the connection should be considered.