根据帮助整理的：方法一：制作 mnf文件时添加step1:用按 ansys制作自由摸态的 mnf文件（old.mnf）step2:用记事本制作预载荷文件(load.txt)格式如下：%PC 节点添加预载（初始值）1000 FX 1e5 1000号节点 X向加 100000N1001 FY -1e5%C 节点添加载荷（恒定值）1000 FX 1e5 1000号节点 X向加 100000N1001 FY -1e5%PM 模态添加预载10 1e5 1000号模态加 100000N%M 模态添加载荷10 1e5 1000号模态加 100000Nstep3:用命令行执行命令生成含有预载荷的 mnf文件(new.mnf)格式如下：%mdi -c flextk mnfload old.mnf new.mnf load.txt step4:用 ADAMS定义 modal force,选用 funtion方法二：编写用户子程序添加step1:用 fortran或 C+写 MFOSUB函数，生成 ADAMS/solver的 dll（详情参考论坛相关帖子）step2:用 ADAMS定义 modal force,选用 subroutine,并输入函数参数和 dll的路径（期待高手完善）补充例子如下：一根梁两端固定，中间某排节点添加向下的集中力方法一：制作 mnf文件时添加step1:用按 ansys制作自由摸态的 mnf文件（old.mnf）命令流如下：/PREP7 ET,1,SOLID95 ET,2,MASS21 R,1,1e-6,1e-6,1e-6,1e-6,1e-6,1e-6, MPTEMP, MPTEMP,1,0 MPDATA,EX,1,2e11 MPDATA,PRXY,1,.3 MPTEMP, MPTEMP,1,0 MPDATA,DENS,1,7800 BLOCK,0,0.01,0,0.001,0,0.002, K,10001,0,0.0005,0.001 K,10002,0.01,0.0005,0.001TYPE,1VSWEEP,1TYPE,2KMESH,10001KMESH,10002ASEL,S,5NSLA,S,1NSEL,A,818nplotCERIG,818,ALL,UXYZ, allsel,allASEL,S,6 NSLA,S,1NSEL,A,819nplotCERIG,819,ALL,UXYZ, allsel,allstep2:用记事本制作预载荷文件(load.txt)文件内容如下：%C389 FY -100132 FY -100133 FY -100134 FY -100464 FY -100（注意上面的东西不能多也不能少，连回车和空格也不例外，否则导致生成失败）step3:用命令行执行命令生成含有预载荷的 mnf文件(new.mnf)运行 cmd.exe执行以下命令：adams05 flextk mnfload old.mnf mew.mnf load.txt执行完毕信息：E:testexample_modal_forceadams05 flextk mnfload old.mnf new.mnf load.txtBegin execution of MSC Flex Toolkit (mnfload).Title:Name : ct_tempType : ANSYS 11.0Comment 1:Comment 2:Comment 3:Exporting frequency range -1.000000e+000,1.000000e+008Creating a Modal Neutral File with the following information:Nodal Coords YesElement Faces YesEigenvalues YesMode Shapes YesGlobal Mass Properties YesNodal Masses YesNodal Inertias YesGeneralized Stiffness NoGeneralized Mass NoGeneralized Damping NoMode Transformation YesStress Modes YesInterface Nodes YesInertia Invariants NoModal Preload NoModal Loads YesStrain Modes YesNode info:Count: 819Global body properties:Mass : 0.000158Center of Mass: 0.005000 0.000506 0.000987Inertia Tensor: 0.000002 0.000000 0.0000000.000000 0.000002 0.0000000.000000 0.000000 0.000002Eigenvalue info:Modes: 18Trans Mode info:Modes: 18Nodes: 819Writing Mode ShapesNodal inertia info: Sparse matrix entries: 6Units:Mass: KILOGRAMLength: METERTime: SECONDForce: NEWTONNumber of Element Faces: 720Stress Mode info:Modes: 18Nodes: 240Strain Mode info:Modes: 18Nodes: 240step4:用 ADAMS定义 modal force,选用 funtion分析结果