RecurDyn provides various options (Simulation Parameters).
In most of the cases, you can use the default values as they are. But sometimes you may need to change the options
In this article, brief explanation about each options will be described. You can refer to the manual for the details.
Yellow ones are the parameters used frequently.
For the basic solver parameters, please refer to the below articles.
- Solver – Becoming an Experienced User #1, First Episode: Learn about Maximum Time Step!
- Solver – Becoming an Experienced User #2 – Dynamic/Kinematic Analysis Parameters (General)
- Solver – Becoming an Experienced User #3 – Dynamic/Kinematic Analysis Parameters (Parameters)
- Solver – Becoming an Experienced User #4 – Simulation Parameter #1
- Solver – Becoming an Experienced User #5 – Simulation Parameter #2
1.Number of Core
- In general, the default (Auto) would be good enough.
- RecurDyn supports SMP. So you can use the multi-core. This option allows you to decide the number of the cores for the simulation.
- In general, the default (DLL) would be good enough.
- This is the option which was developed for 32 bit environment. So it is rarely used in 64bit environment. And The the speed of DLL type is faster.
3.Linear Solver Type for MBD
- In general, the default (Automatic) would be good enough.
- In V8R5, the name of this option was ‘Use Sparse Solver for MBD’
- Usually, Dense solver is suitable for the simple model and Sparse solver is suitable for the complicated model.
- If Automatic option is used, RecurDyn automatically decide which option to use between Dense and Sparse solver.
- Time offset: This value is used for the TIME variable used in the Function Expression. Time offset is added to ‘TIME’ during simulation. This is especially useful when ‘Extract’ is used.
- If Tolerance: This is used for IF function in the Function Expression. This is used as a tolerance to compare the values. Usually, the default value is good enough.
- When the initial velocity of a body and the initial velocity of a joint are applied at the same time (Body1 in the attached model)
- Relative: The initial velocity of a body is applied with the higher priority.
- Absolute: The initial velocity of a joint is applied with the higher priority.
- How the Initial velocities of the bodies are decided
- Relative: If the initial velocity of a body is not specified, then RecurDyn internally calculate it. (It can be non-zero)
- Absolute: If the initial velocity of a body is not specified, RecurDyn sets them to zero internally.
- For example, in the attached model, the initial velocity of Trajoint2 is 100,
- Relative: Body2 and Body3 moves at the initial velocity 100.
- Absolute: Body2 moves at 100, at Body3 doesn’t move.
- In general, the default (Every Step) is good enough.
- Every Step: Redundant constraint can change depending on the status of the system. So RecurDyn checks the redundant constraint at every step.
- Once at simulation start: This is an option for the compatibility with the legacy model. RecurDyn checks the redundant constraint at the beginning of the simulation once.