Affection analysis of adding incorrect support on the inner force and deformation of roof truss

During the building of cold-formed steel roof truss, vertical support was added on the lower chord of roof truss, which turn the statically determinate structure into statically indeterminate structure. The calculation results show that the inner force status of roof truss is changed because the tensile lower chords become beam-column members and some tensile members become compressive members, which makes the composite stress of some members closed or larger than the material strength and is bad for the safety of roof truss.