異響性能前期設計預防︱採用 ANSA & META建模，E-line方法來分析

05-08

編者按：E-line方法的一個核心思維就是求解兩個相鄰部件之間在時域內的相對位移，並依此計算值為評估異響風險的參數，但有一個問題就是怎麼來設定這個平均值（Mean value）為相對參考值？恐怕還是離不開多個參考車型資料庫（Competitive

vehicle database）的積累才能給出相對合理的參數。

我們都知道異響的模型對後門結果又很大的影響，尤其是幾何形狀複雜的塑料件，相比通常CAE模擬所採用的Hypermesh前處理軟體，ANSA在網格質量調整方面，有強大的自動調整功能，還提供了多種手動網格調整工具。其次，ANSA具有豐富的CAD介面，能方便的和各種CAD進行數據交流。尤其是對UG,CATIA,pro-e主流CAD的介面方面。同時，ANSA提供了批處理數據傳輸的能力，這一點比Hyperworks要快的多。

不妨談一談你的想法和應用感受。

ANSA / META 工具欄中的E-lines方法

The BETA CAE Systems software suite offers a complete toolbox for setting up a ready to run model for analysis using the E-LINE method, and evaluating the results. Through it ANSA pre-processor and META post-processor, it is possible to streamline the process and achieve significant benefits in terms of process time reduction and

simulation quality.

E-Lines的創建

An E-Line in ANSA is a 3D curve that lays between the two components of interest, along which their relative displacement is evaluated under a specific load.

The ANSA pre-processor offers a functionality to select the areas of interest and build the corresponding E-Lines manually. Moreover, analysts can employ the automated

tool to identify and create automatically all possible E-Lines in a complete model.

ANSA軟體中的E-Lines管理器

ANSA has implemented a special tool that offers to the analyst a compact and user friendly interface for the general handling of the E-lines. Specifically, the E-Lines Manager of ANSA, through its interface, can guide the user to not only define easily the needed settings for each E-Line but also offers the ability of a bulk production of the respective FE-Representations. These representations correspond to the available solver keywords.

所支持的求解器

The model set up through ANSA pre-processor is possible both for NASTRAN and LS-DYNA. Considering NASTRAN, RBE3-CBUSH-RBE3 are being created each one oriented by a COORD_NODES_R local coordinate system. As far as LS-DYNA is concerned, *ELEMENT_BEAM_ELFORM_6 are created each one oriented by a *DEFINE_COORDINATE_NODES_DIR_Z and all of them tied to the master and slave area by a *CONTACT_TIED_NODES_TO_SURFACE.

META中的後處理

The META post-processor offers the ability through a special tool, the Squeak and Rattle toolbar, to present, in various ways, the results of the solution. 2D plots and histograms of the relative displacement either for a specific pair of nodes or for the

whole E-LINE can be created. Moreover, contour and vector plots offer the

representation of the results on the 3D model. Finally, reports can be automatically created to inform the analyst if phenomena of Squeak and Rattle exist in the simulation model.

使用META中的異響工具條來繪製相對位移曲線

Using the META Squeak and Rattle toolbar, the analyst can plot massively for all selected E-Lines, the relative displacement between all the corresponding pairs of nodes. As a result, one can have an overview of how a specific phenomenon, either Squeak or Rattle, is developed along the gap between two components.

彩色圖和相位顯示圖例

Another functionality which is really important for Squeak and Rattle analysis is the interaction with the 3D model. Once the user has loaded the geometry of the simulation model in META, the Squeak and Rattle toolbar enables the analyst to select the desired E-Lines and have the geometry in contour or vector plot according to the respective results of relative displacement.

Color map圖結果評價和報告生成

META Squeak and Rattle toolbar offers the ability to run on a full model analysis and produce a Contour plot having as criteria the existence or not of Squeak or Rattle and

simultaneously build automatically a report that contains in tables all the data needed.

採用BETA CAE模擬的優點

The BETA CAE Systems software suite, having incorporated dedicated tools for Squeak and Rattle analyses offers a complete toolset for facilitating and streamlining the S&R CAE processes offering benefits such as:

Time reduction during pre-processing through the automated identification and

creation of E-LINEs.
The control, manipulation and bulk E-LINE realization of numerous 3D curves is
significantly facilitated through the E-LINEs Manager further facilitating the
process and saving additional time.
Model set up is available for both NATRAN and LS-DYNA.
The capabilities offered by the META post processor for automatic reports creation,
direct demonstration of the results on the components of interest, and the instant
general overview of the most crucial areas almost eliminates post-processing
effort and duration.