ABSTRACT
A truss has a designed geometry and an as-built geometry. Displacement of nodes from their designed positions can be caused by manufacturing or construction errors. Displacement of nodes from their as-built positions is induced by applied loads or temperature changes. Truss deŒection refers to either deviation from the designed positions or from the as-built positions. No matter what is the cause for deŒection, one or more members of the truss may have experienced a change of length. Such a change of length makes it necessary for the truss to adjust to the change by displacing the nodes from its original position as shown in the following ™gure. Truss deŒection is the result of displacements of some or all of the truss nodes, and nodal displacements are caused by the change of length of one or more members.
