Analytical Model for Lateral Load Effect on Buildings

A mathematical analysis of the elastic deformations and stresses in a vierendeel truss with different chords is presented. The equations of recurrence for the slopes at panel points of both chords are established and from them is formulated the finite difference equation of the panel drift angle. The different parts of the corresponding solutions are classified and their meaning analyzed. Comparison of results encountered with expressions related to a simpler type of structure suggests a frame analogy that leads to a new type of analytical model consisting of a half frame. The solution of the equivalent structure yields with good accuracy the drift angles and the sum of the cross member end moments at the actual structure. The concept of the frame analogy is extended to multiple chord vierendeel trusses, thereby establishing a simple analytical model to solve the lateral load analysis in multistory buildings. Numerical examples illustrate the use and advantages of the proposed technique.