MotionSolve

Highlights

MotionSolve is a state-of-the-art multibody solver available in HyperWorks. It has a complete set of modeling elements and powerful numerical methods to support a full set of analysis methods. The accuracy, speed and robustness of MotionSolve have been validated through extensive testing with customer models and test data. MotionSolve also offers unmatched compatibility with ADAMS/Solver input.

In version 2017, MotionSolve brings new capabilities, added functionalities to the existing capabilities and improvements in performance.

The 2017 release of MotionSolve enables you to define rigid body contact between two curves that are each defined in two dimensions. Simulating rigid body contact in two dimensions between two curves is advantageous when:

•	It is known a-priori that the contact occurs only within the plane in which the two curves are defined i.e. there are no out-of-plane contact forces that are expected.

•	The curves between which the contact is to be calculated are smooth and represent the curvature of the 3D geometry well

The advantages of simulating rigid body contact using 2D curves over 3D tessellated geometry are many:

•	More accurate results: Results are more accurate since there is lesser error due to discretization. Discretization of a 3D geometry into triangles occurs over 3 dimensions as opposed to 2 in curves

•	Easily improve accuracy: Accuracy of the results can be improved quicker by introducing more points in the curve within MotionView.

Improving the accuracy of results when using 3D contact requires you to re-import the graphic and re-mesh or go outside the MotionView environment into a CAD tool to re-mesh. Re-meshing a 3D geometry will certainly take more time than refining a 2D curve.

•	Faster simulation times: For geometries where contact occurs over a curve, using a curve-curve contact is a lot faster than using a 3D tessellated geometry since the solver has to work harder to determine contact for a 3D tessellated geometry which increases the overall simulation time

For more details on how curve-curve contact can be defined and solved in MotionView and MotionSolve, please refer to the respective user and reference manuals.

Parallelization has been enabled for certain operations within the default linear solver in MotionSolve. For models that take a large time to simulate, you should expect to see an improvement in linear solution time. The overall speedup in simulation time will be model dependent and will be influenced by pre/post processing times, time spent in user subroutine calls along with the time spent in the linear solution.

Included in the documentation accompanying MotionSolve 2017 is a validation manual for the Non-Linear Finite Element capability in MotionSolve. The goal of this validation manual is to compare simulation results from models that include NLFE elements to known, analytical results.

The validation manual is available as part of the user’s guide for MotionSolve. Also included in the HyperWorks installation are models that are used in the validation manual. Please refer to the user’s guide for more information and the location of these models.

Previously, the solver time step for models running kinematic analyses was determined by the output step size. If your model contained event sensors, the only way to increase the accuracy of the sensors was to reduce the output step size which would result in larger output files (mrf, h3d etc.). Simulations like these thus demanded a lot of disk space, if the simulation end time was large, or if the model was simulated repeatedly.

With the current release, this behavior has changed. If your kinematic model contains event sensors, you may now specify a solver time step that is different from the output step size by using the parameter h_max. This lets you control the size of your output files independent from the accuracy of the sensors in your model.

Failure in Quasi-static analysis

With the previous release, a failure in analysis was observed for a class of models that contained massless bodies and ran quasi-static analysis. This was identified as a bug and has been fixed with the current release.