ANSYS刚性区域的建立.doc

刚性区域的建立 关于CERIG命令的用法(转)CERIG命令是用来限制两个节点的自由度,但是不是约束,是使两个节点的某些或全部自由度具有相同的值,即通常说的刚化.CERIG, MASTE, SLAVE, Ldof, Ldof2, Ldof3, Ldof4, Ldof5Defines a rigid region.要选取主节点(MASTE)和副节点(SLAVE),Ldof和后面的是想要刚化的自由度.本来很简单的命令,但是还是有一些使用限制.By setting Ldof to ALL on the CERIG command (default), this operation will generate three equations for each pair of constrained nodes in 2-D space. These equations define the three rigid body motions in global Cartesian space (UX, UY, ROTZ). In order to create a rigid region on a 2-D model, you must make sure that the X-Y plane is the rigid plane and that UX, UY, and ROTZ degrees of freedom are available at each constrained node. This operation will similarly generate six equations for each pair of constrained nodes in 3-D space. All six degrees of freedom (UX, UY, UZ, ROTX, ROTY, and ROTZ) must be available at each constrained node.Entering other labels in the Ldof field will create different effects. If this field is set to UXYZ, the program will write two constraint equations in 2-D (X, Y) space and three constraint equations in 3-D (X, Y, Z) space. These equations will be written in terms of the slave nodes translational degrees of freedom, and in terms of the master nodes translational and rotational degrees of freedom. Similarly, the RXYZ label allows you to generate a partial set of equations that omit the slave nodes translational degrees of freedom. The other available Ldof labels will generate other types of constraint equations.In general, your slave nodes need have only the degrees of freedom called for by Ldof, but your master node must have all applicable translational and rotational degrees of freedom (that is, UX, UY, ROTZ for 2-D; UX, UY, UZ, ROTX, ROTY, ROTZ for 3-D). For models that are made up of elements having no rotational degree of freedom, you might consider adding a dummy beam element to provide rotational degrees of freedom at the master node.上面的英文我不翻译了,主要是最后一段,你的副节点只需要有需要刚化的自由度,但是你的主节点必须要有所有的平移和旋转自由度,例如UX, UY, ROTZ for 2