=======================
Matricial Pinned Joints
=======================


------------
Introduction
------------

The Matricial pinned joints processes pinned joints by checking nodes loads
against **fixed location** for pins. This is very different from the *sliding
*method*, where no assumptions on the pin location is done.

------
Method
------

For each joint, a "n x m" matrix is built where *n* is the number of nodes involved
in the joint, and *m* the number of pins. This sparse matrix defines
a *node vs. pin* participation factor for each node.

This participation factor is based on the relative distances between the two
closest fixations:

.. figure:: /plugins/mpjoints/fig/participation_factor.png
    :align: center
    :alt: simple pipeline
    :figclass: align-center

    Participation factor

---------
Allowable
---------

The allowable are extracted from *Carnac* database. The tricky part is to "fill
the gaps". To do it, nasca will base its search on the following panels
properties:

A, B
    respective reference (*e.g. NB220-0155-500*) for panels A and B.

thkA, thkB
    respective thickness for panels A and B.

manA, manB
    respective manufacturer (*e.g. Nordam, JCB, etc.*) for panels A and B.

typeA, typeB
    respective type (*e.g. epoxy, alu, phenolic, etc.*) for panels A and B.

Nasca will search for an allowable in the following order:  

1. search allowable for A / B
#. search for critical values for the pair: A / [typeB, manB, thkB] and [typeA, manA, thkA] / B.
#. search for critical values for the pair: A / [typeB, manB] and [typeA, manA] / B.

Example
"""""""

We need an allowable for the following pair: "jcb-ep-216-115-500", "nb220-0155-375",

* First try:
    search for "A=jcb-ep-216-115-500 B=nb220-0155-375 shape=L pitch=4" returns nothing
* Second try:
    search "A=jcb-ep-216-115-500 manB=nordam thkB=0.375 typeB=epoxy shape=L pitch=4" returns nothing
    search "manA=jcb thkA=0.5 typeA=epoxy B=nb220-0155-375 shape=L pitch=4" returns nothing
* Third try:
    search "A=jcb-ep-216-115-500 manB=nordam typeB=epoxy shape=L pitch=4" returns:

+-------+-------+--------+----+-------+------+--------------------+----------------+------+--------+------+------+-------+-------+-----------+
| shape | pitch | vector | ab | value | unit | A                  | B              | manA | manB   | thkA | thkB | typeA | typeB | unit_from |
+=======+=======+========+====+=======+======+====================+================+======+========+======+======+=======+=======+===========+
| L     | 4     | L      | A  | 617   | lbf  | jcb-ep-216-115-500 | nb220-0155-750 | jcb  | nordam | 0.5  | 0.75 | epoxy | epoxy | lbf       |
+-------+-------+--------+----+-------+------+--------------------+----------------+------+--------+------+------+-------+-------+-----------+
| L     | 4     | S      | A  | 342   | lbf  | jcb-ep-216-115-500 | nb220-0155-500 | jcb  | nordam | 0.5  | 0.50 | epoxy | epoxy | lbf       |
+-------+-------+--------+----+-------+------+--------------------+----------------+------+--------+------+------+-------+-------+-----------+
| L     | 4     | T      | A  | 414   | lbf  | jcb-ep-216-115-500 | nb220-0155-500 | jcb  | nordam | 0.5  | 0.50 | epoxy | epoxy | lbf       |
+-------+-------+--------+----+-------+------+--------------------+----------------+------+--------+------+------+-------+-------+-----------+

    search "manA=jcb typeA=epoxy B=nb220-0155-375 shape=L pitch=4" returns nothing

-------------
Configuration
-------------

Configuration options are located at: Analysts/mpjoints

----------
Gids loads
----------

Nodal loads are retrieved from result file "Grid Point Force Balance" sections.
If option ``loads_from_mpc`` is False, which is default, loads are retrieved from CQUAD and
and CTRIA. If this option is True, the loads are retrived from MPC
(RBEs).

The loads retrieved by Nasca can be checked from FEMAP by using the freebody
functions, as shown below:

.. figure:: /plugins/mpjoints/fig/freebody_options.png
    :align: center
    :alt: femap freebody options
    :figclass: align-center

    Femap Freebody Options