Flexible Bodies in ViewFlex

ViewFlex uses assumed modes method of modeling flexible bodies - the same method used in Adams Flex. This method of representing flexible bodies is called modal flexibility.

Modal flexibility assigns a set of mode shapes, frequency eigenvectors, to a flexible body. The flexible body modeling element designates a system state variable to each eigenvector and calculates the relative amplitude of each eigenvector during a time-domain analysis. The principle of linear superposition is then used to combine the mode shapes at each time step to reproduce the total deformation of the flexible body.

This modal method of modeling flexibility can be very useful when it comes to problems which are characterized by high elasticity and moderate deflections (deflections less than 10% of a characteristic length of the body). Modal flexibility also provides a means of directly correlating Adams flexibility results with FEA results.

Because ViewFlex uses a modal representation of the flexible bodies exclusively, the ViewFlex online help refers to them simply as flexible bodies.

In addition, all the modeling techniques and restrictions for Adams Flex also apply to ViewFlex. For example, some forces and joints cannot be directly connected to a flexible body, and these vary by solver type. Sometimes this requires a workaround like introducing an intermediate dummy part that is fixed to the flexible body. For more details on what is supported by solver type for connections to flexible bodies, see Connecting Flexible Bodies to Your Model in the Adams Flex guide.