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I'm carrying out a constant radius analysis and have changed the hard points only, given the following input for the analysis 

the errors that I'm getting is 

 

ERROR: At time=1.401E-08 the integrator failed to proceed.

----------- Possible Causes -----------------------------------------------------
(1) The integration has become unstable. Tighten (decrease) integr_tol, h_max,
or both in Param_Transient can help stabilize the integration. If the simulation
contains distinctive phases, use multiple Simulate, each with its
own proper integrator parameter setting, to selectively tighten the tolerance
during the period where instability is encountered.
(2) If the simulation was terminated because stepsize has diminished consistently
below h_min, reduce h_min in Param_Transient to force integration to continue.
(3) Non-physical inertia properties, such as mass=100 Kg and Ixx=Iyy=Izz=1 Kg*mm^2,
or extremely small inertia on a part with an unconstrained degree of freedom.
Make sure the modeling data, in particular the part inertia and the gravity, are
specified in proper units consistent with the units given in Param_Unit element.
(4) Beam, flexible body goes out of linear range, bushing has large rotation along
more than one axis, curve goes out of its interpolation range, higher-pair joint
goes out of the range of U or V, etc. Make sure fundamental modeling assumptions,
such as rigid contact assumption used in Force_Contact, are not violated.
(5) Motion displacement defined using LINSPL, AKISPL in dynamic analysis, or as a
function of model states (DX, VX etc), as well as forces defined as a function of
other forces, can cause hard convergence and integrator failure. Avoid these
modeling practices wherever possible.
---------------------------------------------------------------------------------

ERROR: Abnormal return from transient analysis

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Hi Adrian,

Looking at this message only without knowing the model is not possible to identify the error.

Does MS write a .h3d animation? Did you check if it is ok during statics?

When changing the hard points, did you keep the symmetry making sure left and right are correct?

 

Maybe you could upload the model.

Best regards,

Felipe.

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If you only changed hardpoints, without updating mass information, spring rates, and spring preload, etc, it's possible that your vehicle is not built in a way to expect reasonable initial conditions.  Since the simulation is failing right at time t=0, this is the most logical explanation based on the info you have provided.

 

A common practice is to build half-car models before building a full vehicle model.  Then we run the half-car models through basic analysis like static ride, or Kinematics and compliance, to ensure the model is robust, and has the correct corner weights on the wheels, etc.  Then, when we assemble the full vehicle model, there is a highly likelihood that the model will run successfully.

 

Also, it is better to run more basic, open loop analysis before constant radius.  I will usually run straight line acceleration as my first full vehicle event.  Starting with simpler events also assists with debugging the initial model.

 

Chris 

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Hello Felipe

 

 

Yes, it does write a .H3D file and it has a default option for transient, I don't know how you could change it to static.

Yes, the model is symmetric and the spring stiffness and preload and mass inputs are given. 

How do I calculate the moment of inertia, do we calculate it about the body's origin OR from the CG of the vehicle. 

Can you please send me your private file sharing link and will it be confidential?. 

Edited by adriannunes
since I did not address the problem completely

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I'm getting these errors when I carry out a static ride analysis on transient mode and have set the weight of the components and spring stiffness and changed the hardpoints for it.


 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!
 ERROR: GTCMAT not supported during dynamic analysis, it will be set to zero!

INFO: Analysis model processed.

 Partitioning generalized coordinates...

INFO: Total Number of Independent Coordinates  = 54
 Generalized coordinates partitioned. Continue with initializing model...

INFO: Number of Total Entries in Residual Vector: 3240
INFO: Number of Non-zero Entries in Jacobian Mtx: 20751 (0.197674% Filled)
INFO: Number of Entries Associated with VarCoord: 38 (0.183124%)

WARNING: NaN encountered from User-Request/80000040:Component/4! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000050:Component/6! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000080:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000110:Component/3! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000180:Component/8! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000190:Component/8! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000200:Component/3! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000210:Component/7! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000220:Component/6! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000270:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000310:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000320:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000330:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000340:Component/2! Future warnings will be suppressed.

WARNING: NaN encountered from User-Request/80000350:Component/2! Future warnings will be suppressed.


 Starting dynamic analysis. . . 

 

DYNAMIC SIMULATION PARAMETERS
 ----------------------------------------
 Start Time                   : 0.000E+00
 End   Time                   : 1.000E+01
 Print Interval               : 1.000E-01

 Integrator                   : DSTIFF
 Error Tolerance              : 1.000E-03
 Maximum Step Size            : 1.000E-02
 Minimum Step Size            : 1.000E-06
 DAE Index                    : 3
 DAE Constraint Tolerance     : 1.000E-05

 Time=6.250E-04; Order=1; H=6.250E-04 [Max Phi=1.178E-07]
 Time=1.034E+00; Order=4; H=1.000E-02 [Max Phi=1.455E-07]
 Time=2.034E+00; Order=4; H=1.000E-02 [Max Phi=4.095E-10]
 Time=3.034E+00; Order=4; H=1.000E-02 [Max Phi=9.240E-12]
 Time=4.034E+00; Order=3; H=1.000E-02 [Max Phi=7.403E-12]
 Time=5.134E+00; Order=3; H=1.000E-02 [Max Phi=3.867E-12]
 Time=6.134E+00; Order=3; H=1.000E-02 [Max Phi=4.594E-12]
 Time=7.134E+00; Order=2; H=1.000E-02 [Max Phi=2.558E-12]
 Time=8.134E+00; Order=3; H=1.000E-02 [Max Phi=5.457E-12]
 Time=9.134E+00; Order=3; H=1.000E-02 [Max Phi=4.775E-12]
 Time=1.000E+01; Order=3; H=5.625E-03 [Max Phi=2.111E-12]

 DAE SOLVER STATISTICS (DASPK-Index3)
 ------------------------------------------------
 Number of solution steps                     = 1013
 Number of residue evaluations            = 1083
 Number of jacobian computations      = 8
 Number of error test failures                = 2
 Number of nonlinear convergence failures = 0

 

and then created a H3D file in which the jacks did not move. 

 

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The static ride analysis contains user subroutines that rely on running a static analysis.  You should run the static ride analysis as a static solution, not transient.

 

If you can switch off all of the outputs that rely on user subroutines, you and probably get the analysis to run, but this really isn't the purpose of the static ride analysis event.

adriannunes likes this

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On 7/23/2019 at 9:15 PM, Chris Coker said:

If you only changed hardpoints, without updating mass information, spring rates, and spring preload, etc, it's possible that your vehicle is not built in a way to expect reasonable initial conditions.  Since the simulation is failing right at time t=0, this is the most logical explanation based on the info you have provided.

 

A common practice is to build half-car models before building a full vehicle model.  Then we run the half-car models through basic analysis like static ride, or Kinematics and compliance, to ensure the model is robust, and has the correct corner weights on the wheels, etc.  Then, when we assemble the full vehicle model, there is a highly likelihood that the model will run successfully.

 

Also, it is better to run more basic, open loop analysis before constant radius.  I will usually run straight line acceleration as my first full vehicle event.  Starting with simpler events also assists with debugging the initial model.

 

Chris 

What do you mean by model being robust and correct weight on the wheels?

I have also carried out the Static ride and K&C and have got the results.

should I carry the same process with the rear and then carry on with the full car assembly?

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Under Tools -> CG/Inertia summary, MotionView can calculate the overall CG and moment of inertia of your model.  It is typically calculated about the origin, but you can calculate it with respect to another reference frame if you need to.

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