Shell Element (4 node) Example 01

Introduction:
(If you want to skip the intro, click here)

The Usfos Shell element is a  fully non linear element available in both static and dynamic analyses. Both material non linearity and non linear geometrical effects are accounted for, and the material properties are temperature dependent (optional).

For theory description, it's referred to the following papers:

• Thin Walled Structures, 2001 
• Thin Shell
• Dynamic behaviour (extract from Diploma thesis, Dec 2000)

 The shell has following properties, some few (bold) are mandatroty, the rest are optional:

• Nonlinear Material
• Geometry (plate thickness)
• Eccentricities (node offsets)
• Pressure Load (non conservative)
• Shell Load (conservative)
• Temperature Load

Shell Element Behaviour:

Always "non linear". Real Physics always switched ON, (Detects Yielding, Buckling etc). No "linear" switch exists, (increasing the E-mod and Yield Stress is the way to surpress non linear (real) behaviour). 

Element results available from Xfos:

• Element Utilization (0-1)
• Effective Plastic Strain (upper an lower side)
• Effective Stress (upper and lower side)

The results are selected from the Result/Genernal Menu: 

The Nodal result is averaged nodal values, while the Element Results  is the highest value found withing the element (integration point values). 

Axially Loaded Shell.

=> Usfos Control File
=> Structural File

• Node 1 and 4 fixed in X-direction, Node 1 free in Y-direction.
• Concentrated X-force in Node 2 and 3.  

                Initial Shape                                             Stretched / Contracted

                                  Force - Displacement