我想对图中画红圈的地方施加一个按正弦规律变化的载荷，但不知道命令流怎么写 下面是我写得命令流，最后面是关于施加正弦载荷的地方，但是不能运行，请大神更正一下 finish /clear,all /prep7 et,1,beam188 mp,ex,1,2.1e11 mp,prxy,1,0.3 SECTYPE, 1, BEAM, HREC, , 0 SECOFFSET, CENT SECDATA,0.5,0.5,0.02,0.02,0.02,0.02 k,, k,,,5 k,,,10 k,,,15 k,,,20 k,,5 k,,5,5 k,,5,10 k,,5,15 k,,5,20 k,,5,,5 k,,5,5,5 k,,5,10,5 k,,5,15,5 k,,5,20,5 k,,,,5 k,,,5,5 k,,,10,5 k,,,15,5 k,,,20,5 k,,7.887 k,,7.887,,5 l,1,5 l,6,10 l,11,15 l,16,20 *do,i,1,4,1 l,1+i,6+i l,6+i,11+i l,11+i,16+i l,16+i,1+i *enddo l,12,22 l,7,21 LESIZE,ALL,0.1, , , ,1, , ,1 lmesh,all /solu *do,i,1,16,5 dk,i,all *enddo DK,21, , , ,,UX,UY DK,22, , , ,,UX,UY antype,4 !瞬态分析 trnopt,full !选择完全法 TIME,720 DELTIM,0.1, , ,1 kbc,0 outres,all,all fk,5,fx,20000*sin(3.14/2*{TIME})