对于单个弹簧,可采用如下关键字来建立模型
*ELEMENT_DISCRETE
当然,现在LS-DYNA提供了离散梁单元来模拟弹簧,且可同时考虑三个平动,三个转动
及质量,和阻尼,比较全面;
在LS-DYNA帮助中明确说出,推荐用离散梁单元,对于单离散弹簧单元以后不再继续开发;
当采用离散梁单元时，关于集中质量可不在梁单元上施加，可直接通过质量单元加到相关节点上来；
当模型中有多个弹簧时，如一个线弹簧和一个转动弹簧，这时如果用离散单弹簧单元在后处理时只能得到一个弹簧的结果（一直没弄清楚是不是软件问题，在数据文件里有，但在读取时得不到）；而在前处理中如果用 ANSYS建模的话，弹簧单元必须从单元号1开始，否则一直报错，非常差异，这个也一直没弄清楚是不是软件问题，还请高人分析！
下面是几个模型,分别用这两种不同单元建立的:
采用离散弹簧单元:
采用离散梁单元:
从图中可以看出,两者结果基本一致,但是由于离散弹簧单元在结果输出精度上受质量和刚度大小影响,因此输出点数量较少,而离散梁单元则可通过调整后处理数据数量而得到更好结果
离散单弹簧单元模拟时：
*KEYWORD
*TITLE
$
*DATABASE_FORMAT
0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ NODE DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*NODE
1 0.000000000E+00 0.000000000E+00 0.000000000E+00 0 0
2 1.000000000E+03 0.000000000E+00 0.000000000E+00 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ SECTION DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SECTION_DISCRETE
1 0 0.0000 0.0000 0.0000 0.0000
0.00 0.00
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ MATERIAL DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*MAT_SPRING_ELASTIC
1 1.000E+04
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ PARTS DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
*PART
Part 1 for Mat 1 and Elem Type 1
1 1 1 0 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ ELEMENT DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*ELEMENT_DISCRETE
1 1 1 2 0 0.000000000E+00 0 0.000000000E+00
*ELEMENT_MASS
2 2 20.00000000E+06
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ COORDINATE SYSTEMS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ LOAD DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DEFINE_CURVE
1 0 1.000 1.000 0.000 0.000
0.000000000000E+00 0.000000000000E+00
2.000000000000E+02 1.250000000000E+05
1.000000000000E+03 1.250000000000E+05
*SET_NODE_LIST
1 0.000 0.000 0.000 0.000
2
*LOAD_NODE_SET
1 1 1 1.000 0 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ RIGID BOUNDRIES $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ BOUNDARY DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SET_NODE_LIST
2 0.000 0.000 0.000 0.000
1
*BOUNDARY_SPC_SET
2 0 1 1 1 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTACT DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTROL OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTROL_ENERGY
2 2 2 2
*CONTROL_HOURGLASS
1 0.100
*CONTROL_SHELL
20.0 1 -1 1 2 2 1
*CONTROL_BULK_VISCOSITY
1.50 0.600E-01
*CONTROL_TIMESTEP
0.0000 0.6700 0 0.00 0.00
*CONTROL_TERMINATION
1000. 0 0.00000 0.00000 0.00000
*DATABASE_HISTORY_NODE
1
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ TIME HISTORY $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_RWFORC
0.1000
*DATABASE_GLSTAT
0.1000
*DATABASE_DEFORC
0.1000
*DATABASE_MATSUM
0.1000
*DATABASE_NCFORC
0.1000
*DATABASE_RCFORC
0.1000
*DATABASE_DEFGEO
0.1000
*DATABASE_SPCFORC
0.1000
*DATABASE_SWFORC
0.1000
*DATABASE_BNDOUT
0.1000
*DATABASE_RBDOUT
0.1000
*DATABASE_GCEOUT
0.1000
*DATABASE_SLEOUT
0.1000
*DATABASE_JNTFORC
0.1000
*DATABASE_BINARY_D3PLOT
0.1000
*DATABASE_BINARY_D3THDT
0.1000
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ DATABASE OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_EXTENT_BINARY
0 0 3 1 0 0 0 0
0 0 0 0 0 0
*END
离散梁单元模拟时：
*KEYWORD
*TITLE
$
*DATABASE_FORMAT
0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ NODE DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*NODE
1 0.000000000E+00 0.000000000E+00 0.000000000E+00 0 0
2 0.000000000E+00 1.000000000E+03 0.000000000E+00 0 0（此节点可不定义，但在单元中的第2节点应输-N1，详见后红色部分）
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ SECTION DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SECTION_BEAM
1 6 1 -2
1 0.00 0.00 0.00 0.00 0.00
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
*MAT_linear_elastic_discrete_beam
1 1 1.00000e4 1.00000e4 1.00000e4
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ PARTS DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
*PART
Part 1 for Mat 1 and Elem Type 1
1 1 1 0 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ ELEMENT DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*ELEMENT_BEAM
1 1 1 2（若2节点未定义，此时输-1，代表弹簧另一端固接于大地，此时后面无需施加约束）
$
*ELEMENT_MASS
2 2 20.000000E+06
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ COORDINATE SYSTEMS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ LOAD DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DEFINE_CURVE
1 0 1.000 1.000 0.000 0.000
0.000000000000E+00 0.000000000000E+00
2.000000000000E+02 1.250000000000E+05
1.000000000000E+03 1.250000000000E+05
*SET_NODE_LIST
1 0.000 0.000 0.000 0.000
2
*LOAD_NODE_SET
1 1 1 1.000 0 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ RIGID BOUNDRIES $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ BOUNDARY DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SET_NODE_LIST
2 0.000 0.000 0.000 0.000
1
*BOUNDARY_SPC_SET（若2节点输入-N1，则无需再定义此处的约束）
2 0 1 1 1 1 1 1
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTACT DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTROL OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTROL_ENERGY
2 2 2 2
*CONTROL_HOURGLASS
1 0.100
*CONTROL_SHELL
20.0 1 -1 1 2 2 1
*CONTROL_BULK_VISCOSITY
1.50 0.600E-01
*CONTROL_TIMESTEP
0.0000 0.6700 0 0.00 0.00
*CONTROL_TERMINATION
1000. 0 0.00000 0.00000 0.00000
*DATABASE_HISTORY_NODE
1
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ TIME HISTORY $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_RWFORC
0.5000
*DATABASE_GLSTAT
0.5000
*DATABASE_DEFORC
0.5000
*DATABASE_MATSUM
0.5000
*DATABASE_NCFORC
0.5000
*DATABASE_RCFORC
0.5000
*DATABASE_DEFGEO
0.5000
*DATABASE_SPCFORC
0.5000
*DATABASE_SWFORC
0.5000
*DATABASE_BNDOUT
0.5000
*DATABASE_RBDOUT
0.5000
*DATABASE_GCEOUT
0.5000
*DATABASE_SLEOUT
0.5000
*DATABASE_JNTFORC
0.5000
*DATABASE_BINARY_D3PLOT
0.5000
*DATABASE_BINARY_D3THDT
0.5000
*DATABASE_BINARY_D3DUMP
2846
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ DATABASE OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_EXTENT_BINARY
0 0 3 1 0 0 0 0
0 0 4 0 0 0
*END
Author: Taochun Yang
佐雍得尝，与众分享，收获快乐！
