abaqus隱式分析中contact control設置問題以及后處理中輸出的strain energy為負值切較大的問題
模擬一層預浸料彎曲變形，使用的是S4單元，
contact control設置如下
仿真完成之后creat xy data
ALLSD和ALLSE
其中ALLSD隨著時間步數值如下：
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隨著時間步如下
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
而動能ALLKE卻一直未零！！
abaqus幫助文檔里面的說明如下：
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.
大概意思是設置contact control可以有助于收斂，可是結果需要自己來驗證，可以用ALLSD與ALLSE的比值來判斷結果的準確性，可是我這個ALLSE是負值，雖然絕對值很大。
使用的s4單元，排除了沙漏能造成能量為負的原因
我的問題是我的結果是否可靠呢？幫助文檔里面說的對比ALLSE和ALLSD是用的是絕對值來對比嗎？
阿瓦隆號 
