Review article

In accordance with the recommendations for the design of crane secondary trusses, torsion forces in the lower chord are determined as in a single-span beam. The inclusion of web elements in the truss is not taken into consideration. The purpose of the study is improvement of the method for preliminary calculation of the lower chord during torsion. The disadvantages of the current method of determining internal forces in the lower chord of the truss are given. Methods for determining the forces taking into consideration the reinforcing effect of the truss web elements are proposed. The forces and stresses obtained by analytical calculations, numerical studies and in-situ inspection are compared. Recommendations for the preliminary and verification calculation of the crane secondary truss are given.