Conditions symbols file (.sim)

Files with the extension .sim comprise different symbols to represent some conditions during the preprocessing stage. You can define these symbols by creating ad hoc geometrical drawings and the appropriate symbol will appear over the entity with the applied condition every time you ask for it.

One or more symbols can be defined for every condition and the selection will depend on the specified values in the file, which may be obtained through mathematical conditions.

The spatial orientation can also be defined in this file, depending on the values taken by the required data. For global definitions, you have to input the three components of a vector to express its spatial direction. GiD takes these values from the corresponding conditions window. The orientation of the vector can be understood as the rotation from the vector (1,0,0) towards the new vector defined in the file.

For line and surface conditions, the symbols may be considered as local. In this case, GiD does not consider the defined spatial orientation vector and it takes its values from the line or surface orientation. The orientation assumes the vector (1,0,0) to be the corresponding entity's normal.

These components, making reference to the values obtained from the adequate conditions, may include C-language expressions. They express the different field values of the mentioned condition as cond(type,i), where type (real or int) refers to the type of variable (not case-sensitive) and i is the number of the field for that particular condition.

Example: Creating the Symbols file

Here is an example of how to create a symbols file. Create and edit the file (problem_type_name.sim in this example) inside the problem_type_name directory (where all your problem type files are located). Except for the extension, the names of the file and the directory must be the same.

The contents of the problem_type_name.sim example should be the following:

cond Point-Constraints

3

global

cond(int,5)

1

0

0

Support3D.geo

global

cond(int,1) && cond(int,3)

1

0

0

Support.geo

global

cond(int,1) || cond(int,3)

cond(int,3)

cond(int,1)*(-1)

0

Support-2D.geo

cond Face-Load

1

local

fabs(cond(real,2)) + fabs(cond(real,4)) + fabs(cond(real,6))>0.

cond(real,2)

cond(real,4)

cond(real,6)

Normal.geo

This is a particular example of the .sim file where four different symbols have been defined. Each one is read from a ***.geo file. There is no indication of how many symbols are implemented overall. GiD simply reads the whole file from beginning to end.

The ***.geo files are obtained through GiD. You can design a particular drawing to symbolize a condition and this drawing will be stored as problem_name.geo when saving this project as problem_name.gid. You do not need to be concerned about the size of the symbol, but should bear in mind that the origin corresponds to the point (0,0,0) and the reference vector is (1,0,0). Subsequently, when these ***.geo files are invoked from problem_type_name.sim, the symbol drawing appears scaled on the display at the entity's location.

Nevertheless, the number of symbols and, consequently, the number of ***.geo files can vary from one condition to another. In the previous example, for instance, the condition called Point-Constraints, which is defined by using cond, comprises three different symbols. GiD knows this from the number 3 written below the condition's name. Next, GiD looks to see if the orientation is relative to the spatial axes (global) or moves together with its entity (local). In the example, the three symbols concerning point constraints are globally oriented.

Imagine that this condition has six fields. The first, third and fifth field values express if any constraint exist along the X-axis, the Y-axis and the Z-axis, respectively. These values are integers and in the case that they are null, the degree of freedom in question is assumed to be unconstrained.

For the first symbol, obtained from the file Support3D.geo, GiD reads cond(int,5), or the Z-constraint. If it is false, which means that the value of the field is zero, the C-condition will not be satisfied and GiD will not draw it. Otherwise, the C-condition will be satisfied and the symbol will be invoked. When this occurs, GiD skips the rest of the symbols related to this condition. Its orientation will be the same as the original drawing because the spatial vector is (1,0,0).

All these considerations are valid for the second symbol, obtained from the file Support.geo, but now GiD has to check that both constraints (&&) - the X-constraint and the Y-constraint - are fixed (their values are not zero).

For the third symbol, obtained from the file Support-2D.geo, only one of them has to be fixed (||) and the orientation of the symbol will depend on which one is free and which one is fixed, showing on the screen the corresponding direction for both degrees of freedom.

Finally, for the fourth symbol, onbtained from the file Normal.geo, it can be observed that the drawing of the symbol, related to the local orientation will appear scaled according to the real-type values of the second, fourth and sixth field values. Different types of C-language expressions are available in GiD. Thus, the last expression would be equivalent to entering '(fabs(cond(real,2))>0. || fabs(cond(real,4))!=0. || fabs(cond(real,6))>1e-10)'.

Note: As previously mentioned, GiD internally creates a project_name.geo file when saving a project, where it keeps all the information about the geometry in binary format. In fact, this is the reason why the extension of these files is .geo. However, the file project_name.geo is stored in the project_name.gid directory, whereas these user-created ***.geo files are stored in the problem_type_name.gid directory.