MFBD (Multi Flexible Body Dynamics) in RecurDyn is a technology to analyze the dynamic behavior of systems which include both rigid bodies and flexible bodies. It combines MBD (Multi-Body Dynamics) to analyze the motion of rigid bodies and FEM (Finite Element Method) to analyze the motion, stresses, and deformation of flexible bodies. RecurDyn’s solver combines with these two components in a single solver. This provides RecurDyn with a much faster and much more robust solver than it could be achieved through co-simulation.
Two flexible body formulations are supported in MFBD in RecurDyn. One is the method of modal synthesis, in which the deformation of a body is represented by a set of linear mode shapes obtained from an eigen analysis of the flexible body. The other is the nodal method, in which all nodal degrees of freedom are considered. The nodal method supports both nonlinear geometric deformation as well as nonlinear material formulations, such as plastic and large-strain rubber-like hyperelastic materials. RecurDyn’s powerful analysis environment combines both the modal and the nodal methods into the same solver, giving RecurDyn an incredibly robust, fast, and reliable solver.
Furthermore, flexible body meshes can be either imported from externally created FE meshes, or the meshes can be conveniently created directly inside of RecurDyn using its built-in mesh engine. RecurDyn is the first Multi-Body Dynamics analysis code to incorporate a mesher, allowing the user great flexibility and convenience in MFBD modeling and analysis.
MBD (Multi-Body Dynamics) Analysis
A Multi-Body Dynamics analysis is the analysis of the motion over time of a system of rigid bodies interconnected by joints and acted on by forces, and possibly driven by user-defined motions of specific bodies in the system. The forces acting on the bodies can be inter-body forces, like springs or contact, or externally applied forces, such as gravity or a driving force. RecurDyn provides an intuitive, easy-to-use environment for modeling and analyzing Multi-Body Dynamics.
Features of MBD (Multi-Body Dynamics) Analysis in RecurDyn
- Simple and easy to model a specified motion, force, joint, or contact.
- Intuitive modeling and composition of mechanism elements and configurations of mechanical systems.
MFBD (Multi Flexible Body Dynamics) Analysis
A multi flexible body dynamics analysis is a simple extension of Multi-Body Dynamics in RecurDyn. An MFBD analysis can be composed by swapping flexible bodies for rigid ones. MFBD analysis capitalizes on the advantages of MBD analysis in RecurDyn, such as ease of modeling joints and external forces. The motion of the flexible bodies as well as the resulting stresses, strains, and deformation of these bodies can be examined directly from the results of an MFBD analysis in RecurDyn.
Features of MFBD (Multi Flexible Body Dynamics) Analysis in RecurDyn
- Rigid and flexible bodies can be easily connected together in the same model.
- The number of bodies to be treated as flexible can be adjusted, as well as the flexible body formulation between the modal and nodal methods. This allows for simulation time to be optimized based on the needs for fidelity in the results.
- Boundary conditions and forces applied to the flexible parts are controlled much more naturally and much more accurately than they are using rigid bodies to estimate the forces to be applied to isolated parts in finite element analysis afterward.
- Connections, joints, and force elements are preserved when converting a rigid body to a flexible one.
- A rigid body in a RecurDyn model can be easily replaced with a mesh from other FE software.