CONSIDERATION ON TRUSS AND SPLICE JOINT DESIGN MODELS IN EXTREMAL LOADING

Abstract

In this study the behavior of elements and joints in hard loaded Warren trusses is analyzed theoretically with the purpose of disclosing the sections and elements which possibly can become extremely stressed under the design load proposed being real before the ultimate limit state. The significance of truss topology selected has been brought forth, since unfavorable loading of a tensioned chord connection is discussed in this paper. Three types of tensioned splice joints have been examined considering expected elongations of bolts in order to determine additional stresses induced due to the redistribution of tensile forces. An assumption of a continuous beam model on elastically deformed discrete supports has been adopted as a design model for the examination of stresses possibly caused in the sections of bolts. It has been proved that a joint with extended end-plates over both flanges of chord I profile may be accepted as the one which is safe and robust enough for use in tensile chords of bearing structures. The joint type with end-plates extended over a more tensioned flange only and the one with connecting bolts all hidden between flanges has been subjected to sharp criticism due to the extremely nonuniform behavior and the overloading of bolts. The results of this numerical case study promote a deeper understanding and help assessing the endplate joint behavior since they lack the uniqueness of the solution recommended by the building codes, which is particularly significant when hard-loaded structures have been designed for covering the spans of public building areas.