# Panel Connections (compmech.panel.connections)#

Connection between panel domains. Each panel domain has its own set of Bardell approximation functions. Below it is shown the connections currently supported.

## kCBFycte#

Connection of type:

                     _
|
|| --> Flange       |
||                  |-> Can be used to model a stiffener
======  --> Base      |
_|


ycte indicates the connection exists at a constant $$y_1$$ for panel 1 (base) and $$y_2$$ for panel 2 (flange).

## kCSB#

Connection of type:

======        ==> base
------        --> skin


Takes into account the offset between the two mid-surfaces.

## kCSSxcte#

Connection of type:

__________
|        |
|        |      /^\ x2
|   S2   |       |
|        |   y2  |
|        |   <----
|________| (connection at x2=xcte2)
__________ (connection at x1=xcte1)
|        |
|        |      /^\ x1
|   S1   |       |
|        |   y1  |
|________|   <----


## kCSSycte#

Connection of type:

           /-> (connection at y1=ycte1)
/
/  /->(connection at y2=ycte2)
_________| |_________
|        | |        |
|        | |        |
|   S1   | |   S2   |
|        | |        |
|________| |________|

/^\ x1       /^\ x2
|            |
y1  |        y2  |
<----        <----


## Calculating Penalty Constants#

Function :func:’.calc_kt_kr’ is based on Ref [castro2017AssemblyModels] and uses a strain compatibility criterion to calculate penalty constants for translation (kt) and rotatio (kr). The aim is to have penalty constants that are just high enough to produce the desired compatibility, but not too high such that numerical stability issues start to appear.

compmech.panel.connections.calc_kt_kr(p1, p2, connection_type)[source]#

Calculate translation and rotation penalty constants

For details on how to derive these equations, see [castro2017AssemblyModels].

Parameters:
p1Panel

First panel.

p2Panel

Second panel.

connection_typestr
One of the types:
• ‘xcte’

• ‘ycte’

• ‘bot-top’

• ‘xcte-ycte’: to a 90° connection

• ‘ycte-xcte’: to a 90° connection

Returns:
kt, krtuple

A tuple with both values.