Abstract: In view of the existing blindness of one-sidedly pursuing the use of high-strength and low-density materials in the practice of attempting lightweighting of vehicle structure at present, the maximum deflection and the strength limit of the beam structures with three different cross sections, following different mass reduction modes are studied by theoretical analysis and calculation under a condition of uniformly-distributed loading with a fixed support on one end and a roller support on the other end, to obtain the lightweighting limit of beam structures with different cross sections, providing references for the lightweight design of structure

Key words: structure, lightweighting, stiffness, strength, limit