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Transition elements, BEAM71S1

Problem description: The cantilever beam shown is subjected to uniformly distributed loading ly, lz per unit length and the end force Fx, Fy, Fz. Calculate deflection and stresses for two load cases: i) the in-plane problem using lyFxFy only and ii) the complete three-dimensional loading ly, lz, Fx, Fy, Fz.

\begin{figure}
\centering\hspace{0pt}
\epsfclipon\epsfxsize=6cm\epsffile{beam56s1.ps}
\end{figure}

Mesh: Two hexahedra, two semi-loofs--see appendix B.4.
Material properties: $E=2\times 10^5$ MPa, $\nu=0.3$.
Support: Clamped at x=0. Statically determinate.

u=v=w=0 node:	 1 
u=w=0 nodes: 	 2 25       
u=v=0 nodes: 	 4 28       
u=0 nodes: 	 3 26 27      
Loading: Given as

ly=-100 lz=200 unit: N/m 
Fx=20000 Fy=-20 Fz=10 unit: N      
Solution: The end force acts on edge L3 of the semi-loof element number 4, therefore it is replaced with the equivalent edge traction as in example II.5

\begin{displaymath}l_x=\frac{20000}{0.02}=1000\times 10^3\,\mbox{[N/m]}~,~~~
l_y=-10^3\,\mbox{[N/m]} ~,~~~
l_z=0.5\times 10^3\,\mbox{[N/m]}
\end{displaymath}

The distributed loading in y direction acts on faces S3 of the hexahedral elements number 1, 3 and on edges L2 of semi-loofs 2, 4. Following examples II.4, II.5 we replace this loading with the surface traction

\begin{displaymath}q_n(\verb*\vert S3\vert)=\frac{l_y}{0.01}=-0.01\times 10^6\,\mbox{[Pa]}
\end{displaymath}

for elements 1, 3 and the edge traction

\begin{displaymath}l_{xh}(\verb*\vert L2\vert)=l_y=-100\,\mbox{[N/m]}
\end{displaymath}

for elements 2 and 4.

Finally, the distributed loading in z direction is replaced with the surface traction

\begin{displaymath}q_n(\verb*\vert S2\vert)=q_n(\verb*\vert S1\vert)=
-\frac{l_z}{0.02}=-0.01\times 10^6\,\mbox{[Pa]}
\end{displaymath}

acting on faces S2, S1 of elements 1, 3 and 2, 4, respectively.
 
Execute from prompt:
>rmd3 beam71s1.I1
>rpd3 beam71s1.I2
>srh3 beam71s1.I3
>fefs beam71s1.I4
>str3 beam71s1.I5


 
next up previous contents
Next: INPUT Up: Elastostatics Previous: OUTPUT