I.4.8 “calcResultingFM” method

“calcResultingFM” method is a class method used to estimate the total force and moment corresponding to a distribution of forces and moments on several points. The method has between 4 and 6 arguments:

1.

A DataBase object containing the model used to calculate the total forces and moments.

2.

A first Result object corresponding to the vectorial forces.

3.

A second Result object corresponding to the vectorial moments.

4.

An object corresponding to the coordinate system in which results and position of recovery point are expressed. If the argument is an integer, it must correspond to the index of a CoordSys object defined in the dataBase. The argument can also be a CoordSys object, but its definition must refer a coordinate system defined in the dataBase.

5.

A vector (Array of three real values) corresponding to the position of the point wrt which the total force and moment are calculated. The position of the point is defined wrt the coordinate system corresponding to the previous argument. (This may different than what other post-processing tools like Patran do.)

6.

A Result object corresponding to the coordinates of the connections that are used to estimate the global moment. (See additional remarks below.)

Note that the two last arguments are optional:

• If argument 5 is omitted, the method assumes that the recovery point is located on the origin of the coordinate system.
• I argument 6 is omitted, the nodal coordinates are used to estimate the global moment corresponding to the nodal forces ($M={\sum <!--FUNCTION\; APPLICATION-->}_i{x}_i\times f_i$). Then, the forces used to estimate the global moment must be associated to nodes.

The sixth parameter containing the coordinates must be associated to the same Result keys as the forces Result. The parameter can be very useful when the forces are not associated to nodes. This is, for example, the case when the forces correspond to CBUSH element forces. For example, let us assume that the coordinate Results have been generated in the database:

The coordinates corresponding to the forces can be obtained as follows:

And the global force and moment calculated as follows:

If argument Results are in Real format, the method returns an Array containing two vectors (i.e. two Arrays of Real objects). These vectors correspond to the total force and total moment respectively. Note that the method produces no new Result object.

If argument Results are Complex, the method returns an Array containing two Complex vectors (i.e. two Arrays of Complex objects). Note However that the Complex values in the resultants are always given in rectangular format (real and imaginary parts). This is true even when the argument Results are in polar (magnitude-phase) format.