ANALYSIS OF SEMI-RIGID BOLTLESS BEAM-TO-COLUMN CONNECTORS IN STEEL STORAGE RACKS

摘要

Storage racks are three-dimensional load bearing structures for the storage and retrieval of goods in warehouses. Compared to traditional steel structures, steel storage racks have two main differences: the continuous perforated cold-formed steel columns and semi-rigid boltless hook-in connectors. The connector, welded to each end of the beam, has hooks or other devices which engage in slots in the column. The connectors from different manufacturers have different geometry and performance, so it is difficult to develop a generalized analytical method. In this study, three series of tests were conducted on a commercially available connector. The objective of tests is to study the stiffness and ultimate strength of the connector subjected to bending, shear or tensile force. Both moment-rotation curves from bending tests and load-displacement curves from shear or tensile tests are highly non-linear. The finite shell element models that simulate the experimental behaviour closely were developed using ANSYS finite element software. According to the test failure phenomena that the hooks in tension side cut in the columns web, a simplified calculation model has been developed, using the springs to replace the effect of hooks. Based on the model, the formulas, calculating the moment resistance and initial rotational stiffness of connectors, have been proposed. The comparison between experimental results and solutions obtained from the formulas show that the accuracy of the calculation model is acceptable. Thus the calculation model can be used to estimate the connector performance when there is no test data.