The Finite Element Method for the Analysis of Non-Linear and ...
The Finite Element Method for the Analysis of Non-Linear and ...
The Finite Element Method for the Analysis of Non-Linear and ...
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<strong>The</strong> Beam <strong>Element</strong> in Large Displacements<br />
<strong>The</strong> finite element equations in this case are:<br />
t K<br />
⎡<br />
⎢<br />
⎣<br />
.<br />
u k<br />
θ k<br />
.<br />
⎤<br />
⎥<br />
⎦ = t + ∆t R − t F (1)<br />
Having solved Eqn (1) <strong>for</strong> bfu k , θ k , we obtain <strong>the</strong> approximations <strong>for</strong> <strong>the</strong><br />
nodal point displacement <strong>and</strong> direction vectors:<br />
t + ∆t u k = t u k + u<br />
∫ k<br />
t + ∆t V k t = t Vt k + dθ k × τ Vt<br />
k<br />
V<br />
∫ k<br />
t + ∆t V k s = t Vs k + dθ k × τ Vs<br />
k<br />
V k<br />
<strong>The</strong> above <strong>for</strong>mulation corresponds to an iteration <strong>of</strong> <strong>the</strong> Newton-Raphson<br />
method<br />
Institute <strong>of</strong> Structural Engineering <strong>Method</strong> <strong>of</strong> <strong>Finite</strong> <strong>Element</strong>s II 41