<P>梁壳体连接情况的讨论 <BR>1 按“杆梁壳体”的顺序,只要后一种单元的自由度完全包容了前一种单元的自由度,则有公用结点即可,不需要约束方程。例如: <BR> 杆与梁、壳、体有公用结点即可,不需要写约束方程; <BR> 梁与壳有公用结点即可,不需要写约束方程; <BR> 梁与体则要同位置的不同结点,需要耦合自由度和约束方程; <BR> 壳与体则要同位置的不同结点,需要耦合自由度和约束方程; <BR>2 壳梁自由度数目相同,自由度也相同,尽管壳的rotz是虚的自由度,也不妨碍二者之间的关系,这有点类同于梁与杆的关系。 <BR>3 尽管可以采用耦合自由度和约束方程,但建议尽量不同时采用多种单元于一个结构中,除非你对结果的正确性有十足的把握。 <BR>4 当然,采用约束方程可能存在应力集中点,不必在意此点的应力。 <BR>5 我自认为是正确的,希望各位大侠批评指正。 <BR>6 为说明上述说法的正确性,这里提供有5个小例子。例1是全“壳单元”,例2是“梁壳单元”;例3是全“体单元”,例4是“体梁单元”,例5是“体壳单元”。 <BR>7 运行于ansys6.1下,三月雨提供。 <BR>!********************************************** <BR>!梁壳的耦合问题小算例 <BR>!采用壳单元时exam1 <BR>/prep7 <BR>et,1,shell63 <BR>mp,ex,1,3e5 <BR>mp,prxy,1,0.0 <BR>r,1,1.0 <BR>wprota,0,90 <BR>blc4,,,120,10 <BR>aesize,all,2 <BR>mshape,0,2d <BR>mshkey,1 <BR>amesh,all <BR>/view,1,1,1,1 <BR>/ang,1 <BR>eplot <BR>nsel,s,loc,x,0 <BR>d,all,all <BR>nsel,s,loc,x,120 <BR>*get,nhzs,node,,count <BR>f,all,fy,-3/nhzs <BR>allsel,all <BR>/solu <BR>solve <BR>!********************************************** <BR>!梁壳的耦合问题小算例 <BR>!采用梁壳单元时exam2 <BR>/prep7 <BR>et,1,shell63 <BR>et,2,beam4 <BR>mp,ex,1,3e5 <BR>mp,prxy,1,0.0 <BR>r,1,1.0 <BR>r,2,10.0,10/12.0,1000/12.0,10.0,1.0 <BR>wprota,0,90 <BR>blc4,,,60,10 <BR>wpoff,,5 <BR>wprota,,90 <BR>asbw,all <BR>k,100,120,0,5 <BR>ksel,s,loc,x,60,120 <BR>ksel,r,loc,z,5 <BR>*get,kp1,kp,,num,min <BR>kp2=kpnext(kp1) <BR>l,kp1,kp2 <BR>ksel,all <BR>wpcsys,-1 <BR>lsel,s,loc,x,60,120 <BR>latt,1,2,2 <BR>lesize,all,,,10 <BR>lmesh,all <BR>asel,all <BR>aatt,1,1,1 <BR>aesize,all,2 <BR>mshape,0,2d <BR>mshkey,1 <BR>amesh,all <BR>allsel,all <BR>/view,1,1,1,1 <BR>/ang,1 <BR>eplot <BR>finish <BR>!------------------------ <BR>/solu <BR>nsel,s,loc,x,0 <BR>d,all,all <BR>nsel,s,loc,x,120 <BR>f,all,fy,-3.0 <BR>allsel,all <BR>solve <BR>/post1 <BR>etable,zl1,smisc,1 <BR>etable,zl2,smisc,7 <BR>etable,jly1,smisc,2 <BR>etable,jly2,smisc,8 <BR>etable,jlz1,smisc,3 <BR>etable,jlz2,smisc,9 <BR>etable,mx1,smisc,4 <BR>etable,mx2,smisc,10 <BR>etable,my1,smisc,5 <BR>etable,my2,smisc,11 <BR>etable,mz1,smisc,6 <BR>etable,mz2,smisc,12 <BR>!********************************************** <BR>!梁壳体的耦合问题小算例 <BR>!全部采用体单元时exam3 <BR>/prep7 <BR>et,1,solid95 <BR>mp,ex,1,3e5 <BR>mp,prxy,1,0.0 <BR>r,1 <BR>blc4,,,20,7,10 <BR>blc4,20,3,100,1,10 <BR>vglue,all <BR>wpoff,0,3 <BR>wprota,0,90 <BR>vsbw,all <BR>wpoff,0,0,-1 <BR>vsbw,all <BR>wpstyle <BR>/view,1,1,1,1 <BR>/ang,1 <BR>vplot <BR>esize,1 <BR>mshape,0,2d <BR>mshkey,1 <BR>vmesh,all <BR>finish <BR>/solu <BR>asel,s,loc,x,0 <BR>da,all,all <BR>allsel,all <BR>nsel,s,loc,x,119.6,120 <BR>nsel,r,loc,y,4 <BR>*get,nhzs,node,,count <BR>f,all,fy,-3/nhzs <BR>allsel,all <BR>solve <BR>!********************************************** <BR>!梁壳体的耦合问题小算例 <BR>!采用体单元和梁单元时exam4 <BR>/prep7 <BR>et,1,solid95 <BR>et,2,beam4 <BR>mp,ex,1,3e5 <BR>mp,prxy,1,0.0 <BR>r,1 <BR>r,2,10.0,10/12.0,1000/12.0,10.0,1.0 <BR>blc4,,,20,7,10 <BR>wpoff,0,3.5 <BR>wprota,0,90 <BR>vsbw,all <BR>wpoff,0,5 <BR>wprota,0,90 <BR>vsbw,all <BR>wpcsys,-1 <BR>k,100,20,3.5,5 <BR>k,101,120,3.5,5 <BR>l,100,101 <BR>lsel,s,loc,x,21,130 <BR>latt,1,2,2 <BR>lesize,all,,,10 <BR>lmesh,all <BR>vsel,all <BR>vatt,1,1,1 <BR>esize,1 <BR>mshape,0,2d <BR>mshkey,1 <BR>vmesh,all <BR>allsel,all <BR>/view,1,1,1,1 <BR>/ang,1 <BR>eplot <BR>finish <BR>!------------------------ <BR>/solu <BR>asel,s,loc,x,0 <BR>da,all,all <BR>allsel,all <BR>fk,101,fy,-3.0 <BR>cp,1,ux,1,21 <BR>cp,2,uy,1,21 <BR>cp,3,uz,1,21 <BR>ce,1,0,626,ux,1,2328,ux,-1,1,roty,-abs(nz(626)-nz(2328)) <BR>ce,2,0,67,ux,1,4283,ux,-1,1,rotz,-abs(ny(67)-ny(4283)) <BR>ce,3,0,67,uz,1,4283,uz,-1,1,rotx,-abs(ny(67)-ny(4283)) <BR>allsel,all <BR>solve <BR>finish <BR>!------------------------ <BR>/post1 <BR>etable,zl1,smisc,1 <BR>etable,zl2,smisc,7 <BR>etable,jly1,smisc,2 <BR>etable,jly2,smisc,8 <BR>etable,jlz1,smisc,3 <BR>etable,jlz2,smisc,9 <BR>etable,mx1,smisc,4 <BR>etable,mx2,smisc,10 <BR>etable,my1,smisc,5 <BR>etable,my2,smisc,11 <BR>etable,mz1,smisc,6 <BR>etable,mz2,smisc,12 <BR>!********************************************** <BR>!梁壳体的耦合问题小算例 <BR>!采用体壳单元时exam5 <BR>/prep7 <BR>et,1,solid95 <BR>et,2,shell63 <BR>mp,ex,1,3e5 <BR>mp,prxy,1,0.0 <BR>r,1 <BR>r,2,1.0 <BR>blc4,,,20,7,10 <BR>wpoff,0,3.5 <BR>wprota,0,90 <BR>vsbw,all <BR>wpoff,20 <BR>blc4,,,100,10 <BR>wpcsys,-1 <BR>vsel,all <BR>vatt,1,1,1 <BR>esize,2 <BR>mshape,0,2d <BR>mshkey,1 <BR>vmesh,all <BR>asel,s,loc,x,21,120 <BR>aatt,1,2,2 <BR>aesize,all,2 <BR>mshape,0,2d <BR>mshkey,1 <BR>amesh,all <BR>allsel,all <BR>/view,1,1,1,1 <BR>/ang,1 <BR>eplot <BR>asel,s,loc,x,0 <BR>da,all,all <BR>allsel,all <BR>cpintf,ux <BR>cpintf,uy <BR>cpintf,uz <BR>ce,1,0,1226,rotz,-abs(ny(197)-ny(742)),197,ux,1,742,ux,-1 <BR>ce,2,0,1276,rotz,-abs(ny(201)-ny(971)),201,ux,1,971,ux,-1 <BR>ce,3,0,1277,rotz,-abs(ny(205)-ny(969)),205,ux,1,969,ux,-1 <BR>ce,4,0,1278,rotz,-abs(ny(209)-ny(967)),209,ux,1,967,ux,-1 <BR>ce,5,0,1279,rotz,-abs(ny(213)-ny(965)),213,ux,1,965,ux,-1 <BR>ce,6,0,1170,rotz,-abs(ny(194)-ny(701)),194,ux,1,701,ux,-1 <BR> <BR>ce,7,0,1226,rotx,-abs(ny(197)-ny(742)),197,uz,1,742,uz,-1 <BR>ce,8,0,1276,rotx,-abs(ny(201)-ny(971)),201,uz,1,971,uz,-1 <BR>ce,9,0,1277,rotx,-abs(ny(205)-ny(969)),205,uz,1,969,uz,-1 <BR>ce,10,0,1278,rotx,-abs(ny(209)-ny(967)),209,uz,1,967,uz,-1 <BR>ce,11,0,1279,rotx,-abs(ny(213)-ny(965)),213,uz,1,965,uz,-1 <BR>ce,12,0,1170,rotx,-abs(ny(194)-ny(701)),194,uz,1,701,uz,-1 <BR>nsel,s,loc,x,120 <BR>*get,nhzs,node,,count <BR>f,all,fy,-3/nhzs <BR>allsel,all <BR>/solu <BR>solve</P> |