Experimental Studies on the Large Plastic Deformation of Frames Due to Horizontal Impact -Measurements of Impact Loading and Vertical Load Effect

An experimental study is made on the nature of the large permanent deformation of the columns in a portal frame under horizontal impact loading. The column specimens were made of mild steel, aluminum alloy and copper plates. The impact load was applied by an input pendulum. The applied load and initial velocity were measured by the barium titanate ceramics, accelerometer and load cell which had been calibrated beforehand from the initial amplitude of a bifilar pendulum. The experimental results show a reasonable consensus with the analysis in which the frame restoring-force characteristics are approximated as bi-linear with a negative second slope.