![]() Further torque pairs can be created which depend on the rotation angle or its first time derivative by means of one-degree-of-freedom elements (spring, damper, plastic laws. This results in a torque on node N1 in the direction of x 1-axis of the hinge joint element and its reaction on node N2. A time dependent torque on node N3 can be specified by means of. CLM NOE I n3 POS COMP 1 VAL- because it is available as a component of a node. However, this new degree of freedom (or its first or second time derivative) can also be prescribed as a function of time using. The first component of node N3 can be printed or stored to plot the time evolution of the rotation angle. If nothing else is made with this node N3, the hinge joint is free. For this reason, it is usually defined with (0,0,0) coordinates. Node N3 has to be defined by the user but has no geometrical meaning. ![]() The rotation angle is a new degree of freedom which is stored by the element as the first component of node N3. The third node of the hinge joint is an angle catcher measuring the rotation angle around the hinge joint axis of node N2 relative to node N1. The hinge joint can be defined with two or three nodes. Hinges can then be replaced by equality constraints between corresponding translational degrees of freedom. In the case of a planar mechanism subjected to in-plane loading the explicit definition of hinge elements is superfluous except for hinges at which a torque is applied or the rotation angle is imposed. MCE HING I element_number N list_of_nodes The minimum definition consists of the element type, the element number and the element nodes according to the following syntax: ![]() The element is defined using the command. If Boolean identification is used, the local axes On the other hand, the use of Lagrange multipliers to express equality conditions allows the access to the reaction forces. The Boolean identification is cheaper because the number of unknowns is reduced but the drawback is that the reaction forces cannot be obtained. The constraints between the translational degrees of freedom of nodes N1 and N2 are imposed either by Boolean identification or Lagrange multipliers. Lagrange multipliers (translation condition, optional) Lagrange multipliers (rotation condition) ![]()
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