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AUTODYN automatically calculates the energy balance and gives an error message when the energy error is greater than the tolerance (default is 5%). First, make sure the grid for all parts is correct before running AUTODYN. Then, carefully examine the material properties used in your AUTODYN calculation. Next, check your boundary conditions. If there are Transmit or Flow in/out boundary conditions defined in your AUTODYN model, a certain material can get out of or into the part, taking away or adding in energy. If this is the case, the energy balance check needs to be disabled in the Controls panel by specifying a very large number like 999999 as the energy reference cycle in the Wrapup Criteria options. This effectively disables the AUTODYN energy error check. If an erosion model is used in Lagrange calculations, both kinetic and internal energy gradually decrease as Lagrange elements erode. This also causes an energy balance error. You can either reset the energy reference cycle to the cycle where you got the energy error in the Controls panel, or disable the energy balance check by setting the energy reference cycle to a very big number, such as 999999. Another possible cause of energy error is that a low mesh density is being used for an area with high internal energy such as an explosive. When the mesh is coarse, numerical error in calculating the internal energy is increased. Refining the coarse mesh or increasing the tolerance of the energy error will help to improve this situation. If the AUTODYN model contains ALE parts and the motion constraint is neither Free (Lagrange) nor Equipotential, select the ALE part from the list in the Parts panel and press the Motions button. Then go to ALE Settings and Modify. Change the Iterations per cycle to a number larger than 1. Thus AUTODYN conducts iterations to rezone ALE grids so at the end of all the iterations they are finally placed on equilibrium positions according their motion constraints. This will also help to reduce energy error. Usually you only need to pay attention to the energy balance if there is a spike in the energy history curve. A summary of the energy balance can be viewed through the History panel by selecting either Energy or Material or Part summaries. |
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Checking model setup…..Please wait
Generating External Faces …… please wait
Initializing…..Please wait
Finished model setup…..
Cycle: 0, Time: 0.000E+00s, Progress: 0.00%, Time Inc.: 8.842E-07s @ element 7888 in Part bmpnframe Est. Cloc
—
Cycle: 1, Time: 9.727E-07s, Progress: 0.00%, Time Inc.: 9.727E-07s @ element 1162 in Part Seat_r Est. Cloc
—
Cycle: 2, Time: 2.043E-06s, Progress: 0.00%, Time Inc.: 1.070E-06s @ element 1162 in Part Seat_r Est. Cloc
2.7 hrs
Cycle: 3, Time: 3.220E-06s, Progress: 0.00%, Time Inc.: 1.177E-06s @ element 1162 in Part Seat_r Est. Cloc
3.0 hrs
Cycle: 4, Time: 4.514E-06s, Progress: 0.00%, Time Inc.: 1.295E-06s @ element 1162 in Part Seat_r Est. Cloc
3.1 hrs
Cycle: 5, Time: 5.938E-06s, Progress: 0.00%, Time Inc.: 1.424E-06s @ element 1162 in Part Seat_r Est. Cloc
3.3 hrs
************************************************************
Cycle: 53759, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Cycle: 53760, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Cycle: 53761, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Cycle: 53762, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Cycle: 53763, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Cycle: 53764, Time: 1.413E-01s, Progress: 56.51%, Time Inc.: 2.622E-06s @ element 1165 in Part Seat_r Est. Cloc
56.1 mins
Problem terminated …. energy error too large
Problem terminated …. energy error too large
********************************************
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Hi
I try to model explosions above a snowpack (for artificial avalanche release). I use a P-alpha eos and an RHT strength and failure constutive model as used for concrete (adapted Drucker-Prager). However, the density (200 kg/m3), stiffness and strength of snow are extremely low. I use an extremely simple axial symmetric geometry (1 meter in x-direction, some meters in y-direction). Nevertheless I encounter many problems with Autodyn:
1) Even with only the material itself (no atmosphere, no loading, no interaction, no gravity), the model does only work with a high energy reference cycle (9999999, «energy error too large» or «time step too small» otherwise) and then still gives stresses although there shouldn’t be any. The material even expands in plus x-direction although there is no load.
2) Adding gravity in minus x-direction does not improve things. And the unit of the gravity in Autodyn is not even specified.
3) I need an atmosphere for the explosion. However, if I add the explosion, the pressure (e.g. 100 kPa at sea level) leads to immediate failure within the snowpack. Naturally, snow is porous and would be loaded hydrostatically by an atmosphere which would not lead to failure. I tried to add the atmospheric pressure to snow’s strength, but this did not help.
4) If I try to produce a two-layer model (two different snow types), I always get overlapping interfaces. As the geometry is so simple, it is drawn in Autodyn itself.
5) Adding a transmit boundary on the y-end of the model does not help. The material still deforms. The same is valid for a velocity boundary (zero velocity) on the y-end. The velocity is anything else then zero, otherwise the material would not deform on that side and lead to cell degeneration.
6) All different models have one thing in common: Stresses oscillate and there are sharp accelerations, although I haven’t used any explosive yet.
Any ideas of how to solve (some of) these issues?
Kind regards,
Stephan
но транзакция не прошла с ошибкой OUT_OF_ENERGY. То есть TRX списало в качестве комиссии, но не хватило видимо, почему-то Exodus позволил провести такую транзакцию, а не предупредил. И дело в том, что сумма в USDT тоже списалась с баланса и не вернулась, будто заморозилась где-то. На отправленный адрес ничего не поступило. На tronscan.io тоже на балансе отсутствует эта сумма. В Exodus писал, но они что-то морочат голову что ли, совсем о другом речь ведут, по их совету пробовал перезагружать блокчейны в кошельке, но не помогло. Кто сталкивался или знает как можно решить эту проблему?
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