concrete\concrete_trilinear.m ........\guaidian1.m ........\guaidian2.m ........\linear.m ........\main_a20.m ........\main_b20.asv ........\main_b20.m ........\main_b20bijiao.m ........\main_vidc.m ........\newmark_single.m ........\nonlinear.m ........\response_l.m ........\response_n.m concrete