Best Of

Re: deciding on upper and lower limit for solving scenario and calculating the losses

Hello Melih,

Thanks for writing. The rules you wrote are correct.

The reason is that especially in the examples, the aim is provide a quick computation, so only one period plus 2 /3 steps are solved. Generally, in fact, with current generators and synch machine, one period plus 2/3 steps are sufficient, since the first two steps where the quantities are affected by the initialization state are not considered.

FluxMotor considers instead 2 periods normally, this is why you found 183.75° [that means 90°x2+INIT_POS].

The reason because you normally find a starting position in the working point computation, is that we need to align the current with the BEMF, to be able to set the phase difference then (GAMMA parameter), as I underlined in the previous question.

Please open a support request if you need to have more explanation.. we could arrange a meeting on this and please don't forget to indicate whether my answer is helpful to you and to mark as resolved the questions for which we have resolved your concerns.

Best regards,

Letizia

Letizia Ferrara

1

Re: Hypermesh Parts Browser Assembly Suppression

Hello Mandy,

Happy new year!

That's actually the suggested way. If you cannot load parts after unloading them, It means they're not available. You'd first need to save them as a representation. Please check the video I'm attaching, I believe that answers your question.

Best regards,
Paulo Libório.

Paulo Libório

1

/DT1TET10について

Radiossなど陽解法ソルバーはわりと計算時間が長くなりがちで、翌日出社して途中でエラーとなっているのを見ると残念な気持ちになりますが、いくつかの経験的な良い設定に準拠して頂くことで多くのエラーは避けることが可能です。その設定については、下記"best practices"としてまとめられておりますので、途中エラーを経験する方は是非一度見て頂きたいと思います。

チュートリアル / ハウツー - Radioss modeling best practices (altair.com)

エラーとなる原因はいろいろあるので一概には言えないのですが、上記"best practices"のほかに、経験的に途中エラーを低減させる効果が高いと感じている設定に、/DT1TET10がございます。エンジンファイル(*＿0001.rad)に/DT1TET10と一行追記頂くだけで要素品質の悪いテトラ2次要素を含むモデルのエラー発生率低減に効果を発揮します。

/DT1TET10 (altair.com)

ヘルプを見ると、「タイムステップ見積もりが一般的に標準より小さくなりますが、不安定性を解決できる可能性があります」との記載があります。

>This time step estimation is generally lower than the standard one, but may solve instability problems.

では、実際にタイムステップはどうなるのでしょうか？確認したのが下の表となります。

この表から、要素品質の良い正四面体2次要素では/DT1TET10の有無に関わらずtime stepは同じですが、要素品質の悪い扁平な潰れた四面体2次要素では(この形では)2割程度time stepが低下するという事がわかります。つまり、全部の要素が正四面体でない場合(事実上ほぼ皆様がそうだと思いますが)、/DT1TET10を追加することで、マススケーリングを設定している場合は追加質量が増加し、マススケーリングを設定していない場合は計算時間が長くなります。

ただ、お客様のモデルを見せて頂くと、複雑なCAD形状や早期に結果を求められることに起因すると思われる潰れがちな四面体2次要素が残っていて、それが原因でエラーとなっていることも多いと感じています。品質の悪い4面体要素周辺が原因と思われるエラーによく遭遇する方は一度お試し頂けますと幸いです。

KOBAYASHI

1

Re: Monarch Classic Will Not Open

@Matt G - thank you for sharing the recommendation tip and glad to hear able to fix @Todd Breckenridge issue.

@Kristen Edge - please know you can also reach out to Contact Altair Technical Support

It has been discovered that their has been a recent MicroSoft update on 12/21 in that users may need to repair or install the Access Engine for Monarch.

Rebecca_Cronin

1

Re: Mapping Displacement/Modal Results

Hello Akhil,

Happy new year!

Fields is supposed to work. I'm sharing a video where I create a 2D beam model from Beam elements and map displacement and rotation results from the 1D Beam model to it. I believe you're looking for something similar.

Let me know if it helps!

Kind regards,
Paulo Libório.

Paulo Libório

1

Re: How the DoF of the stiffnesses K1, K2, K3, K4 , K5, K6 are defined in property PBUSH for the solver Optistruct? and How K values behave in a CBUSH element subjected to loads?

For the CBUSH element, you could do it 2 ways:

- define an orientation vector V (given by X1, X2,X3)

- or define a CID (Coordinate System).

Using a vector, the X-axis of your element is aligned with the spring element. The Y-axis is given by the projection of V (vector product of X and V).

Using CID, you will overwrite this definition with the local system. (leave it 'unespecified' for global system)

Documentation for CBUSH:

https://2021.help.altair.com/2021/hwsolvers/os/topics/solvers/os/cbush_bulk_r.htm