Knuckled Stiffeners

Knuckled stiffeners have a diagonal knuckle line, either extending diagonally across the stiffener or affecting only a part of the stiffener. The knuckle line must not intersect the trace line of the stiffener. Therefore, the trace line of the knuckled stiffener must always be a straight line. The image below shows a couple of typical knuckled stiffeners.

The generation of knuckled stiffeners is activated by the inclusion of the default parameter KNUCKLED_STI[FFENERS] in the default file of Hull Modelling (programs sj001 and sj010). Generation of knuckled stiffeners may occur in three different situations.

1. The stiffener is connected between two other profiles, for example, between a horizontal stiffener on a bulkhead and a "rising" longitudinal, see image below below.

   

   In such a case the need knuckling will be discovered automatically by AVEVA Marine. The knuckle line will be diagonally across the stiffener and placed in such a way that the knuckle line starts at the weld trace in the connection to the shell profile. The knuckle angle will be calculated automatically.

   No special input from the user is required in this case.

2. The second case is that an (inclined) stiffener should end (or start) in a given plane, see image below below (the system supports only that the stiffener is knuckled into one of the principal planes).

   

   The knuckle line will start at the trace at the indicated end of the stiffener and be calculated so that the "triangular" bent piece of the stiffener is, located in the specified plane.

   The stiffener end and the location plane must be defined by the user.

3. The third case is that the position of the knuckle line is controlled explicitly by the user as well as the bending angle, see image below below for a possible case.