When the member load is small, the

When the member load is small, the member is also in the elastic, and its horizontal deformation increases linearly with the load. With the gradual increase in load, the concrete in the draft area first appears transverse cracks and leaves work, and the load and load on the reinforcement far from the axial force accelerates. Then the cracks in the draft area increase and expand to the compression area, the height of the pressure area begins to decrease slowly, and the concrete load in the compression area increases. When the reinforcement far away from the axial force reaches the yield, a headrom is formed in the section. When concrete on the compression side reaches the pressure boundary, longitudinal cracks appear in the weak part of the compression area and the concrete is crushed to destroy the members. At this point, component amplification near the axial power side also reaches the compressive strength.