abaqus隐式分析中contact control设置问题以及后处理中输出的strain energy为负值切较大的问题
模拟一层预浸料弯曲变形，使用的是S4单元，
contact control设置如下
仿真完成之后creat xy data
ALLSD和ALLSE
其中ALLSD随着时间步数值如下：
0 0
0.000758867 1.5037E-010
0.0443268 6.14717
0.291301 3475.9
0.344406 8131.14
0.700145 17450.8
1 17845.1
ALLSE随着时间步如下
0 -2.20256E+008
0.000758867 -2.20256E+008
0.0443268 -2.20256E+008
0.291301 -2.20192E+008
0.344406 -2.20143E+008
0.700145 -2.20087E+008
1 -2.20084E+008
而动能ALLKE却一直未零！！
abaqus帮助文档里面的说明如下：
Although the automatically calculated damping coefficient typically provides enough damping to eliminate the rigid body modes without having a major effect on the solution, there is no guarantee that the value is optimal or even suitable. This is particularly true for thin shell models, in which the damping may be too high. Hence, you may have to increase the damping if the convergence behavior is problematic or decrease the damping if it distorts the solution. The first case is obvious, but the latter case requires a postanalysis check. There are several ways to carry out such checks. The simplest method is to consider the ratio between the energy dissipated by viscous damping and a more general energy measure for the model, such as the elastic strain energy. These quantities can be obtained as output variables ALLSD and ALLSE, respectively. More detailed information can be obtained by comparing the contact damping stresses CDSTRESS (with the individual components CDPRESS, CDSHEAR1, and CDSHEAR2) to the true contact stresses CSTRESS (with the individual components CPRESS, CSHEAR1, and CSHEAR2). If the contact damping stresses are too high, you should decrease the damping. The comparison should be made after contact is firmly established; the contact damping stresses will always be relatively high when contact is not yet or only partially established.
大概意思是设置contact control可以有助于收敛，可是结果需要自己来验证，可以用ALLSD与ALLSE的比值来判断结果的准确性，可是我这个ALLSE是负值，虽然绝对值很大。
使用的s4单元，排除了沙漏能造成能量为负的原因
我的问题是我的结果是否可靠呢？帮助文档里面说的对比ALLSE和ALLSD是用的是绝对值来对比吗？
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