A Comparison of Three Point and Four Point Loading in Elastic-Plastic Bending of Beams

摘要

A comparison between the maximum deflections resulting from beams symmetrically loaded into the elastic-plastic region is presented for the case of three and four point bending. The results indicate that significantly larger deflections can be obtained for the case of four point bending while keeping the maximum fiber strains approximately the same. It appears that using the four point bending approach holds certain advantages in straightening operations for the removal of permanent deflections with the possible elimination of hot straightening in some instances. The concept of distribution of plastic deformation is put forth as a possible explanation of the advantage of one method over the other.