# How to use the Spatial Search Algorithm

(Difference between revisions)
 Revision as of 12:26, 4 May 2012 (view source)Nelson (Talk | contribs) (→Using the Spatial Search Algorithm)← Older edit Revision as of 12:47, 4 May 2012 (view source)Nelson (Talk | contribs) (→The User Configure File)Newer edit → Line 24: Line 24: == The User Configure File == == The User Configure File == + + It say that is the main file created by the user, + which defines the types, and operations contenerdores + necessary to make the spatial decomposition and the search for contacts. + Is then the parameter that defines Bins. + + This consists of four parts: + + *Definition of the types and their containers. + *Function that calculates bounding box + *Function of intersection between objects + *Function of intercession between the object and cells. + + {{Warning| {{Warning|

## Using the Spatial Search Algorithm

Large-scale in Finite Element Methods, Discrete Element Method and Combined Finite-Discrete Element Method simulations involve contact of a large number of separate bodies. Processing contact interaction for all possible contacts would involve a total number of operations proportional to N^2, where N is the total number of separates bodies comprising the problem.

This would be very CPU intensive, and would limit the application that use and need to evaluate the contact forces ,comprising a very small number (a few thousand) of separates bodies. To reduce CPU requirements of processing contact interaction, it is necessary to eliminate couples of discrete elements that are far from each other and are not in contact. A set procedures designed to detect bodies that are close to each other is usually called a contact detection algorithm, or sometimes a contact search algorithm.

With this purpose was created in Kratos Program a contact search algorithm based on spatial decomposition, so it can be used for any application and is unique in that it was implemented in a generic way. Therefore it requires a contact search algorithm having the following characteristics:

• Robust,
• CPU efficient,
• RAM efficient

## The User Configure File

It say that is the main file created by the user, which defines the types, and operations contenerdores necessary to make the spatial decomposition and the search for contacts. Is then the parameter that defines Bins.

This consists of four parts:

• Definition of the types and their containers.
• Function that calculates bounding box
• Function of intersection between objects
• Function of intercession between the object and cells.

 Warning. Please, note that: Saving the name of the class IS NOT NECESSARY anymore. please remove it from the old codes because it will prevent them to be serialized.

## References

• ﻿ Munjiza. Ante, The Combined Finite-Discrete Element Method, John Wiley & Sons, Ltd. 2004