关于"二代龙震工作室的,proe机构结构运动热力分析3.0/4.0"的一个问题.

good0311

红色字体是不是告诉＂创建接触区域，两接触面间距离如何选择呢＂？

Contact — 3D Models
For 3D models, you can create a contact definition between two surfaces. When you select Insert>Connection>Contact, Mechanica asks you to specify the two entities that you want to use.

If you select two surfaces, Mechanica checks for the following on a pass or fail basis:

The distance between the two surfaces must be less than one half the average of the length of the diagonals of the surfaces.

Tip: When creating contacts between surfaces, Structure limits the separation distance and angle between the two surfaces. If you are certain that the two surfaces will eventually contact and you want to work around this restriction, move the surfaces together, define the contact, and then move them apart again.

The surfaces must be no more than 36 off parallel at one point at minimum.

A contact associated with the two selected surfaces cannot already exist.

Mechanica also checks to see if:

the contact defined lies between two interpenetrating volumes.

any curves in common between the two selected surfaces prevents the surfaces from moving completely apart during an analysis. If there are any such curves, a warning box appears and you should respond appropriately.

you are attempting to create a contact on a surface that is on the boundary of two volumes. Applying a contact to this surface allows the volumes to separate.

If you split a surface that two volumes share, you must place contacts on all split surfaces to allow the volumes to separate.

For each valid pair of surfaces, Mechanica places a contact icon at the point where the surfaces are closest to each other, oriented along the point of closest approach.

iampopdeng

我并没有说间距大，应力就一定大，我在四楼的原意是间距不同，结果不同。
对你这个结果，我感觉挺合理的，也挺容易理解的。你可以看一下，每次分析，接触的面积都不同，而   接触力=平均压力*接触面积。
如果接触面积变化，接触力就可能变化，当然应力就可能变化。接触面积变大，接触力就有可能变小。
相关方面，帮助介绍的很详细，mechanica对一些分析有规定，你好好看看吧。

good0311

先谢谢楼上的 ,这个问题我再考虑下.
现在对于这本书" 二代龙震工作室的,proe机构结构运动热力分析3.0/4.0 "里的翻译水平有点不敢恭维了(虽然自己的英语也很差),而且排版顺序也有问题.还得结合PROE帮助看这本书,要不真的很难理解书上在说啥了.
"move the surfaces together"应该是"移动表面到一起"吧.看看书上怎么翻译的."请一起移动表面"

iampopdeng

书上的意思没错，只不过有点机械。
不知道你是否理解mechanica接触的自动侦测接触面的条件。

iampopdeng

这本书对初学者算是不错的了，讲的比较的详细，虽然很多都来自与帮助，也无可厚非，毕竟一上来就看外文，真没那个兴趣啊！
有错误很正常。觉得翻错了的结合帮助来看，对自己也是个很大的提高过程。pro/mechanica的分析能力不足是不争的事实。

good0311

间距和角度条件.
在4.0中,有手动寻找接触面(插入-连接--界面).图一
自动寻找接触面(插入--连接--自动检测并创建接触),图二(这里有限制条件).对于角度条件,我还没有去研究过,因为我作的例子都是平行面了肯定小于5度;对于间距,举例说明.比如有"N对面"间距都小于10,若你在条件框内输入11,则这些面都被选择.
不知道楼上说的是不是这两个条件呢.另外在图一设置里可以切换成图三的样式，不知道图三和图二有什么区别了.

good0311

恩,这方面的中文书籍很少的,这本书算是不错了.这个我也承认,不过还是结合帮助一起学习比较好.

iampopdeng

是。

When creating contacts between surfaces, Structure limits the separation distance and angle between the two surfaces. If you are certain that the two surfaces will eventually contact and you want to work around this restriction, move the surfaces together, define the contact, and then move them apart again.

自动侦测不适用surface-surface，角度在45度之内，具体可查帮助。

You can define Contact Interfaces for reference types, Surface-Surface and Component-Component. For a Surface-Surface reference type, you can choose the surfaces which may come into contact with each other during an analysis. For a  Component-Component reference type, Mechanica creates contacts between any two components that satisfy the criteria specified under Selection Filtering Tolerance.
Note: You can select edges or curves as references, to define a contact interface for 2D models.
You can specify the Selection Filtering Tolerance criteria as follows:
•        Separation Distance — Specify the value for the separation distance or accept the default value which is close to 1% of the model size. The Separation Distance is the maximum distance between the surface pairs that you want to use to define a contact.
•        Angle (between planar surfaces) — Specify an angle or accept the default value of 5 degrees to automatically detect the surfaces for contact definition. You can specify a value in the range of 0 to 45 degrees. You can only check the planar surfaces with the angle control.
•        Check for Contact only between planar surfaces — Click this check box to create contacts only between planar surfaces.
Note: You can specify the Selection Filtering Tolerance only for a component-component contact in an assembly model. You cannot  specify the Selection Filtering Tolerance for a surface-surface contact.
You can specify following Properties for the contact:
•        Split Surfaces — This check box is selected by default. Mechanica splits the surfaces in contact along the boundaries.
•        Generate Compatible Mesh — Click this check box to create a compatible mesh for the surfaces in the contact. This check box is available for selection, when you split surfaces in the contact. In FEM mode, when you split surfaces in the contact, by default Mechanica creates compatible mesh for the surfaces.
Note: If the two surfaces in contact are not compatible, the Split Surfaces check box is not available and you cannot generate compatible mesh for the surfaces.
When you create a contact interface in Mechanica Wildfire 3.0, the surfaces in the contact split by default in Mechanica Wildfire 4.0 if they are compatible and coincident.
•        Infinite Friction — Click this check box if you want to create a contact with infinite friction. The two components or surfaces cannot slide relative to each other.
This option is not available in FEM Mode.

[ 本帖最后由 iampopdeng 于 2009-6-11 11:08 编辑 ]

iampopdeng

也希望把你自己的理解的发上来，大家共同学习学习。

冲锋战神7代

我也在看这本  还没看到那