当前位置:首页 >> 机械/仪表 >>

Femap网格划分 及交互式网格修改


Femap 网格划分 及交互式网格修改
Table of Contents
Overview and Setup ............................................................................................................................

.......... 1 Accessing the Model ..................................................................................................................................... 2 Setting the Mesh Sizes .................................................................................................................................. 2 Meshing the Model ....................................................................................................................................... 4 Interactively Refining the Mesh .................................................................................................................... 6

Overview and Setup
The geometry model for this demonstration is a Femap model file which is based on a Parasolid model of a thin-walled sheet metal part. This model was previously imported into Femap and mid-planes were extracted to create a surface geometry model. The intention of this demonstration is to show how finite element mesh setup, meshing and interactive mesh editing can be applied to create a high quality FE model that will yield accurate results.

As much use as possible has been made of the Model Info tree, toolbars and icons in the user interface to access Femap’s functionality. Usually there is more than one approach that can be employed for any given command. Note that the Parasolid model file was created using millimeters as the unit of length. All references to length in this demonstration therefore are in millimeters.

To ensure that you have all of the necessary icons displayed, a standard layout should be loaded using the Load layout command: Select File Preferences In the Toolbars section of the User Interface tab, select the Load Layout button In the Load Layout From dialog, browse to the workshop directory and select the Workshop.layout file, and click Open and OK

Accessing the Model
Open the Femap model file from the workshop directory Select File Open or select the File Open icon on the Model toolbar, and browse for the Femap model file Femap_BracketMesh_Start.modfem(此文件可从 QQ 群 199022551 下载) – this model file already has some geometry modifications in readiness for meshing

Setting the Mesh Sizes
In this section we’ll activate mesh markers and count, set a default mesh size, override the default by setting a mesh size on surfaces (this activates the count), and set particular mesh sizes for the three washer offset curves on the model. Make sure that the Mesh Size markers are switched on by selecting the drop menu right arrow of the View Style icon in the View toolbar – verify that the Mesh Size icon

is activated in the drop down menu Select View / Options or click the F6 shortcut key and in the View Options dialog within the Labels, Entities and Color category, select Curve – Mesh Size in the Options area In the Show As area of the View Options dialog, select 3..Symbols and Count and click OK Select Mesh / Mesh Control / Default Size and enter a Size of 5. and click OK Select Mesh / Mesh Control / Size on Surface or click on the Mesh Size on Surface icon in the Mesh toolbar In the Entity Select dialog click Select All and OK In the Automatic Mesh Sizing dialog, enter 6.25 for the Elements Size and click OK and Cancel

-

Zoom into the area that contains the three washer offset curves at the front of the model by selecting the Zoom icon in the View toolbar

-

Select Mesh / Mesh Control / Size Along Curve or click on the Mesh Size on Curve icon on the Mesh toolbar, in the Entity Selection dialog select all of the washer offset semi-circular curves and the curves around each of the three holes, verify selection by clicking on the Selection Highlight icon , and click OK

-

Enter 6 for the Number of Elements in the Mesh Size Along Curves dialog and click OK Back in the Entity Selection dialog, select all of the split curves for each of the three holes, and click OK Enter 2 for the Number of Elements in the Mesh Size Along Curves dialog, and click OK and Cancel

-

Select the Previous Zoom icon

on the View toolbar

Meshing the Model
With the preparatory work finished, the next task is to mesh the model.

-

Select Mesh / Geometry / Surface or click on the Mesh Surface icon toolbar In the Entity Selection dialog, click Select All and OK

on the Mesh

-

In the Automesh Surfaces dialog click the Define Property icon In the Define Property dialog click the Define Material icon In the Define Material dialog click the Load button and the Choose Library button

-

Browse to install_directory/femap11/mat_eng_mm-N-tonne-degC-Watts.esp, select and click Open Select 16-25-6 Stainless Steel and click OK

-

Click OK to accept the material definition In the Define Property dialog enter 1.981 for the thickness and click OK In the Automesh Surfaces dialog click OK and the finite element mesh will be created

Interactively Refining the Mesh
Now that the model has been meshed we’ll use the Meshing Toolbox with live element quality checking to verify that the mesh settings defined previously have created as desired and we’ll make some further mesh adjustments interactively. In particular we’ll suppress a hole, merge some split curves and tidy up the mesh using the Mesh Sizing and Mesh Locate capabilities within the Meshing Toolbox. Activate the Meshing Toolbox by clicking the Meshing Toolbox icon Select the Mesh Quality tool in the Panes toolbar

Click on the Quality icon in the header line of icons in the Meshing Toolbox pane Click on the down arrow next to Quality Type Jacobian in the Mesh Quality tool to show that other quality checks are available Expand the tool next to Jacobian by clicking the + sign and set the Max Allowable Value to 0.8 (a more reasonable value for a Jacobian check)

-

Select the Zoom icon in the View toolbar and zoom into the area of the model with the three holes with washer offset curves for which preset curve mesh sizes were set

-

Select the Previous Zoom icon on the View toolbar then select the Zoom icon again and zoom into the area of the model to the right that contained the flange with the pad

-

Select the Previous Zoom icon Select the Zoom icon

on the View toolbar to return to the full model view

in the View toolbar and zoom into the area of the model to the left

-

Click on the Feature Suppression tool in the Meshing Toolbox dialog

-

In the header icons of the Meshing Toolbox select the down arrow next to the Remesh Tools icon and select Auto Remesh

-

Select the Select icon (next to Auto Remesh) To suppress the hole in the flange select both of the defining curves, the hole should disappear and the model remesh automatically, however the defining curves will remain as the hole has only been suppressed and not deleted

-

Deselect the Select icon and rotate the model around to get a better view of the left side – the mesh of the interior corner surface half way up the left side is uneven, and you can see that the defining curves at either end comprise two curves (as created by the CAD system), so we’ll combine each of them into one to get better control of the mesh

-

Select the Combined / Composite Curves tool and reselect the Select icon Select the mid node on the left and right curves of the corner surface – the mesh is still uneven because of the mismatched element count on the top and bottom curves Select the Mesh Sizing tool which will be used to increase the mesh density of the bottom curve

-

Set Operation to Set To and enter 24 for the Number of Elements Select the Select icon and select the bottom curve of the corner surface and deselect the Select icon

-

There is one element to the right just under the corner that is colored red, Select the Zoom icon to zoom in to this element

-

To fix this element we’ll manually drag one of the corner nodes to change the element shape, select the Mesh Locate tool The Select Mesh to Edit entry is currently set to Attached to Surface, click on the down arrow to the right and select Attached to Solid Now click on the icon next to the down arrow, and select the solid (there is only one that comprises all surfaces in this model) In the Select Solid/Volume dialog click OK Select the Select icon Pick and drag the node of the red colored element that is interior to the model, moving it until the element color changes to green

-

Deselect the Select icon

The bracket model mesh is now complete and all elements pass the set quality criterion. Finally to clean up the display select the drop menu right arrow of the View Style icon in the View toolbar and deselect the Mesh Size icon

This concludes the bracket model interactive meshing demonstration.


相关文章:
Femap网格划分 及交互式网格修改
Femap网格划分 及交互式网格修改_机械/仪表_工程科技_专业资料 暂无评价|0人阅读|0次下载|举报文档Femap网格划分 及交互式网格修改_机械/仪表_工程科技_专业资料。...
网格划分步骤及自有网格和映射网格
网格划分的一般步骤:设置单元属性 进行网格划分 检查与修改网格 校验模型与网格单元形状 若划分的单元是体 ?tex(四面体) ? ?? free (自由,非结构化网格划分) ?...
FEMAP 网格划分
FEMAP 网格划分_机械/仪表_工程科技_专业资料。少有的FEMAP 中文资料点击,新建文件 使用命令“投影点” ,绘制直线 如下图输入坐标 0,0,0,点击确定 如下图输入...
deform网格局部细划分探讨
deform网格局部细划分探讨_工学_高等教育_教育专区。deform网格局部细划分探讨网格局部细划分探讨 在网格划分的时候,有时候为了模拟方便和计算精度的提高,需要将局部...
网格划分主要软件
专业通用的网格划分前处理软件,支持大部分有限元分析(FEA)及计算流体动力 学(CFD)软件; 全交互式﹑批处理﹑宏关键字操作;可快速地建立复杂几何物体的网格; ...
网格划分与网格质量检查%%
如果实在不能划分,则退而求其 次,用其他方法进行划分或者对面进行分割;等等。关于体网格的划分,网格划分 所要注意的东西类似。 另外,根据我个人的经验,...
网格划分
MENTAT 的网格划分工具 MENTAT 提供了两类网格划分方法:直接生成单元和由几何形状自动生成 单元。直接生成单元法是给出单元节点位臵和单元节点编码的手动单元生成方 ...
圆柱网格划分V2
圆柱网格划分V2_机械/仪表_工程科技_专业资料。FEMAP 圆柱网格划分个人认为,nastran 是数一数二的求解器,在结构领域,比 ansys 要强很多很多,ansys 在土 木建筑还...
网格划分
网格尺寸过大,不能准确描述应力应变特征,网格尺寸过小,则会增加计算机机时。面对复 杂模型的模拟,这种问题更加突出, 网格的疏密的划分与应力梯度、 应变梯度等有...
【阅】deform网格局部细划分探讨
网格局部细划分探讨 在网格划分的时候,有时候为了模拟方便和计算精度的提高,需要将局部网格细划分, 而其余部分的网格粗分,这样可以减少单元数量,减少计算时间,提高...
更多相关标签:
交互式网格填充 | 交互式网格编辑 | ansys 网格划分 | 网格划分软件 | icem二维网格划分教程 | abaqus网格划分技巧 | hypermesh网格划分 | workbench网格划分 |