ADAMS/Postprocessor中tools下clearance设置详解

hill711 · 发表于 2010-7-14 11:39:18

本帖最后由 hill711 于 2010-7-18 18:32 编辑

原文地址：http://blog.sina.com.cn/s/blog_6203a6df0100kgvl.html
引用请注明！

相信很多人在接触ADAMS开始的时候都为满篇的英文而不知所措，其实真正困难的是如何将理论知识用软件体现，所以大家不必花很长的时间纠缠于各项操作。为了使ADAMS用户快速的掌握各项操作，即符合中国用户的使用，GrantHill工作室将推出各项操作的说明详解。

更多精彩尽在GrantHill工作室：http://blog.sina.com.cn/hill711

本教程详细介绍了ADAMS/Postprocessor中clearance下各项参数的意义及其设置方法，主要用于学习探讨，限于水平，难免有不妥之处，欢迎批评指正！时间有限，请体谅教程的排版！

一、Clearance理解
1、个人见解
Clearance在Adams中的理解为间隙，距离。下面给出词典解释，便于理解。清楚了Clearance的含义有助于学习Adams中的Clearance Study，即间隙分析。通过两种方法给出的解释可知，此处的间隙是构件外部形状上的点到点或点到线面的距离间隙。
通过Clearance Study可以使得不同物体间距离的分析变得简单、快速，特别是在大型装配运动分析过程中检测各个部件之间的运动间隙是否满足设计要求，是否会出现干涉。

2、ADAMS中help文件

路径：2005R2/help/mergedProjects/ppt/clearance/clear2.html
Performing Clearance Studies
You can perform a clearance study that reports the minimum distance between objects in your model at each frame of an animation. For example, you might want to perform a clearance study to ensure packaging requirements are satisfied.
When you view an animation of the clearance study, ADAMS/PostProcessor displays a line between the two objects in the study to track the minimum distance. You can also plot the data and generate reports. For an example of a clearance study, refer to the tutorial in Getting Started Using ADAMS/PostProcessor.
路径：2005R2/help/mergedProjects/ppt/clearance/clear4.html
Running a Clearance Study
When you request to run a clearance study , ADAMS/PostProcessor calculates the minimum and maximum distances between a pair of objects using data from a selected simulation . It adds the information to the animation associated with the simulation, which you can subsequently run. You can also generate a report of the data and plot it.

Tips: The number of frames in your animation can have a significant effect on the accuracy of the distances reported. Therefore, for best results, we recommend that you perform at least one clearance study with a large number of frames in the animation (time steps in the simulation).

To run a clearance study:
1.
Set up the clearance study as explained in Defining a Clearance Study.

From the Tools menu, point to Clearance, and then select Compute.

Clearance Compute dialog box appears.
3.
Select the simulation data against which you want to run the clearance study.
4.
From the pull-down menu, select if you want to calculate the clearance study as if flexible bodies were rigid. This reduces computations and allows the clearance study to run faster but does not give you information about the effects of flexibility.

Select OK.

二、创建（Create）
1、创建过程讲解
即tools下clearance中Create项，如图1所示。

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图1
其中I、J body是在Adams中常见的术语，即不同的两个物体之间。名字（name）符合Adams的命名规则，Maximum设定测量的最大值，超过这个值的部分将不进行计算，且被设定为最大值，例如当Maximum=240时，实际间隙为250的将被设定为240。
方法（Method）有两种方式：Polygon和Vertex两种，两种方法的不同，如图所示。Polygon方法是点与线面间的最短距离，具体表现为：如Ball和Box之间，两者见Clearance连线过球的球心，垂直于Box的表面。Vertex方法是点与点的最短距离，具体表现为：如Plate和Box之间，两者间为距离最近的两个点之间的连线。

图2
2、ADAMS中help文件

路径：search for creat clearance in the Adams help，then choose Create Clearance Dialog Box Defines a clearance study .
Learn more about defining a clearance study.

For the option:	Do the following:
Model	Select the model to be used for the study.
I Body	Select the first object in the pair. You can also select Pick to select the object from the screen. (You can select more than one object at a time.)
J Body	Select the second object in the pair. You can also select Pick to select the object from the screen. (You can select more than one object at a time.)
Name	Enter a name for the study. If you are creating several studies (by selecting more than one I and J body), you can enter a base name for the studies, and ADAMS/PostProcessor will add a suffix to the name (base_1, base_2, and so on).
Maximum	Set the maximum distance for the clearance beyond which clearances will not be computed at any given frame. Leave the text box empty if you always want to calculate the minimum distance.
Method	Select the method for calculating the minimum distances, either: Polygon Vertex

路径：2005R2/help/mergedProjects/ppt/clearance/clear3.html
Defining a Clearance Study
To define a clearance study , you:
·
Select the pair of objects on which you want ADAMS/PostProcessor to report distance information - You select objects, either parts or geometry, to be used in the study. The bodies can be rigid or flexible. You can define many clearance objects at once by selecting multiple objects in the lists.
·
Set maximum distance reported - To reduce the calculations in the clearance study, you can also define a maximum distance above which ADAMS/PostProcessor does not calculate any distance information. When you play an animation, if the distance between the pair of objects is greater than the maximum distance, ADAMS/PostProcessor does not display a line between the objects. In addition, in clearance study reports, if the distance is exceeded at a given frame, ADAMS/PostProcessor records the distance as the maximum distance and not the actual distance.
·
Set method used for calculations - ADAMS/PostProcessor uses two different calculations for clearance studies: polygon and vertex .
To define a clearance study:

From the Tools menu, point to Clearance, and then select Create.

The Create Clearance Study dialog box appears.

Set up the pairs to be investigated in the study.
- In the Model list, select the model to be used for the study.

In the I Body list, select the first object in the pair. You can also select Pick to select the object from the screen. (You can select more than one object at a time.)
o
In the J Body list, select the second object in the pair. You can also select Pick to select the object from the screen. (You can select more than one object at a time.)
3.
Enter a name for the study. If you are creating several studies (by selecting more than one pair of I and J Bodies), you can enter a base name for the studies, and ADAMS/PostProcessor will add a suffix to the name (base_1, base_2, and so on).
4.
Set the maximum distance for the clearance beyond which clearances will not be computed at any given frame. For more information, see the overview on the previous page. Leave the text box empty if you always want to calculate the minimum distance.
5.
Select the method for calculating the minimum distances, either: Polygon or Vertex
6.
Select OK.

Run clearance study as explained in Running a Clearance Study.

三、更改（Changing）
1、更改操作过程讲解
通过在Animation下修改，可以修改可见性、线宽、颜色、方法、最大限制值，如图所示。

图3
2、ADAMS中help文件

路径：2005R2/help/mergedProjects/ppt/clearance/clear8.html
Changing the Clearance Study
You can use the property editor to change many of the aspects of the clearance study and run it again.
To change the clearance study properties:
1.
In the treeview , under the model and simulation on which you selected to perform the clearance study, select the name of the clearance study.
2.
In the property editor, change the following:
o
Visibility - To set the display of the minimum distance line, set Visibility to:

On - Turns on the display of the line during animations.

§
Off - Turns off the display of the line during animations.
o
Inherit - Lets the line simply inherit the display settings from its parent.
o
Line weight - Select a line weight for the minimum distance line. The weight values range from 1 to 5 screen pixels.
o
Color - Set Color to the color for the minimum distance line.
o
Method - Change the method used to calculate the distances: either polygon or vertex .
o
Maximum - Set the maximum value beyond which ADAMS/PostProcessor does not calculate. For more information, see Defining a Clearance Study.

If you changed the method or the maximum value, run the study again as explained in Running a Clearance Study.

四、计算（Compute）

图4
即tools下clearance中Compute项，simulation可以选择已经保存的仿真结果，选择Apply或者OK后，软件会计算已经建立的clearance，如图所示。（PS：每一次建立新的clearance都需要重新计算）
五、保存（Write）
1、保存过程操作详解
即tools下clearance中write项，将保存为htm格式的文件（PS：Adams中经常保存为htm格式的文件）。具体操作及htm格式文件如图5，图6所示。

图5

图6
2、ADAMS中help文件

路径：2005R2/help/mergedProjects/ppt/clearance/clear6.html
Viewing Clearance Data as Reports
You can export summaries of all clearance studies run for a particular simulation in different formats:

The format:	Does the following:	Example:
Complete report in HTML or text format	Displays the objects in the studies, frame at which minimum and maximum distances occurred, and position of objects at minimum distances. The text file has a .clt extension.
Report of minimum distances at each frame in text format	Displays minimum distances at each frame. Has a .clr extension.	Clearance study : CLEARANCE_1 Analysis name : ppt_gs Min 377.083 at frame 11 Max 476.712 at frame 31 Frame Distance --------------------------- 1 420.791 2 420.791 3 412.919 4 405.346 ... Clearance study : CLEARANCE_2 Analysis name : ppt_gs Min 881.402 at frame 11 Max 940.895 at frame 31 Frame Distance --------------------------- 1 912.850 2 912.850 3 907.660 4 902.446 ...