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14.8 $f _ { 1 } = f _ { 3 } = 5 \mathrm { i n } ^ { 3 } / \mathrm { s } , \quad f _ { 2 } = 0$
14.9 $p _ { 2 } = p _ { 3 } = 1 2 ~ \mathrm { m } , ~ p _ { 5 } = 1 1 ~ \mathrm { m }$
# Chapter 15
15.1 d2x ¼ 0:021 in., d3x ¼ 0:042 in., sx ¼ 0
15.2 $d _ { 2 x } = 0 , ~ \sigma _ { x } = 5 0 . 4 ~ \mathrm { M P a }$
15.3 $d _ { 1 x } = d _ { 1 y } = - 0 . 0 1 7 5 \mathrm { ~ i n . , } \quad \sigma ^ { ( 1 ) } = 4 3 5 0 \mathrm { ~ p s i \ : ( T ) }$
$$
\sigma^ {(2)} = - 6 1 5 0 \text { psi (C) }, \quad \sigma^ {(3)} = 4 3 5 0 \text { psi (T) }
$$
15.4 $d _ { 1 x } = - 0 . 0 2 9 1 \ \mathrm { i n . , } \quad d _ { 1 y } = - 0 . 0 0 9 5 \ \mathrm { i n . }$
$$
\sigma^ {(1)} = - 1 3 7 0 \text { psi (C) }, \quad \sigma^ {(2)} = 2 3 7 5 \text { psi (T) }, \quad \sigma^ {(3)} = - 1 3 7 0 \text { psi (C) }
$$
15.5 $d _ { 2 x } = 1 . 4 4 \times 1 0 ^ { - 4 } \mathrm { m } , ~ \sigma ^ { ( 1 ) } = - 2 0 . 2 \mathrm { M P a } \left( \mathrm { C } \right) , ~ \sigma ^ { ( 2 ) } = \sigma ^ { ( 3 ) } = - 1 0 . 1 \mathrm { M P a } \left( \mathrm { C } \right)$
15.6 $\begin{array} { r } { d _ { 1 x } = 0 , d _ { 1 y } = 6 . 0 \times 1 0 ^ { - 4 } \mathrm { m } , \sigma ^ { ( 1 ) } = \sigma ^ { ( 3 ) } = - 1 0 . 5 \mathrm { M P a } ( \mathrm { C } ) } \end{array}$
$$
\sigma^ {(2)} = 1 8. 2 \mathrm{MPa(T)}
$$
15.7 $d _ { 1 x } = 0 , d _ { 1 y } = - 3 . 6 \times 1 0 ^ { - 4 } \mathrm { m } , \sigma ^ { ( 1 ) } = \sigma ^ { ( 2 ) } = 0$
15.8 $d _ { 2 x } = 0 . 0 1 7 3 \ \mathrm { i n . , } \quad \sigma _ { s t } = 8 4 0 \ \mathrm { p s i } \ ( \mathrm { T } ) , \quad \sigma _ { b r } = 1 6 8 0 \ \mathrm { p s i } \ ( \mathrm { C } )$
15.12 $\mathbf { a } . \ - 0 . 0 0 1 9 0 7 \ \mathrm { i n } . \quad \mathbf { b } . \ \sigma _ { b r } = - 2 8 , 6 0 0 \ \mathrm { p s i } , \quad \sigma _ { m g } = - 1 9 , 0 6 7 \ \mathrm { p s i }$
15.13 fT1x ¼ -4464 lb, fT1y ¼ -8929 lb, fT2x ¼ 4464 lb
$$
f _ {T 2 y} = - 8 9 2 9 \mathrm{lb}, \quad f _ {T 3 x} = 0, \quad f _ {T 3 y} = 1 7, 8 5 7 \mathrm{lb}
$$
15.14 $f _ { T 1 x } = - 4 3 . 1 2 5 ~ \mathrm { k N } , f _ { T 1 y } = 0 , f _ { T 2 x } = 4 3 . 1 2 5 ~ \mathrm { k N } , f _ { T 2 y } = - 8 6 . 2 5 0 ~ \mathrm { k N }$
$$
f _ {T 3 x} = 0, \quad f _ {T 3 y} = 8 6. 2 5 0 \mathrm{kN}
$$
15.15 $f _ { T 1 x } = - 6 0 . 0 \mathrm { ~ k i p } , f _ { T 1 y } = - 9 0 \mathrm { ~ k i p } , f _ { T 2 x } = 6 0 \mathrm { ~ k i p } , f _ { T 2 y } = 0 ,$
$$
f _ {T 3 x} = 0, \quad f _ {T 3 y} = 9 0 \mathrm{kip}
$$
15.16 $f _ { T 1 x } = 1 3 4 \ \mathrm { k N } , f _ { T 1 y } = 1 3 4 \ \mathrm { k N } , f _ { T 2 x } = - 1 3 4 \ \mathrm { k N } , f _ { T 2 y } = 0$
$$
f _ {T 3 x} = 0, \quad f _ {T 3 y} = - 1 3 4 \mathrm{kN}
$$
15.17 $\sigma _ { x } = \sigma _ { y } = - 8 9 2 9 \mathrm { p s i } ( \mathrm { C } ) , \tau _ { x y } = 0$
15.18 $\sigma _ { x } = 6 7 . 2 ~ \mathrm { M P a } , \sigma _ { y } = 6 7 . 2 ~ \mathrm { M P a } , \tau _ { x y } = 0$
15.19 $\{ f _ { T } \} = \frac { A E \alpha _ { 0 } } { 6 } \left\{ \begin{array} { r } { - 4 t _ { 1 } - 5 t _ { 2 } } \\ { 4 t _ { 1 } + 5 t _ { 2 } } \end{array} \right\}$
15.20 $\frac { A E \alpha } { 2 } \bigg \{ { - t _ { 1 } - t _ { 2 } } \bigg \}$
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15.21 $\{f_{T}\}=\frac{2\pi\bar{r}AE\alpha(\Delta T)[\bar{B}]^{T}}{1-2\nu}\left\{\begin{array}{l}1\\ 1\\ 1\\ 0\end{array}\right\}$
15.22 $d_{2x} = 0.8 \times 10^{-3}$ in., $d_{3x} = 0$ , $d_{3y} = 0.8 \times 10^{-3}$ in.
$d_{4x} = d_{4y} = 0.8 \times 10^{-3}$ in.; stresses are zero
15.23 $d_{2x} = 0.989 \times 10^{-3}$ in., $d_{3x} = -0.756 \times 10^{-3}$ in.,
$$
d _ {3 y} = 0. 9 8 9 \times 1 0 ^ {- 3} \text { in. }, \quad d _ {4 x} = 0. 1 3 2 \times 1 0 ^ {- 2} \text { in. },
$$
$$
d _ {4 y} = 0. 2 0 4 5 \times 1 0 ^ {- 2} \text {in.}, \quad \sigma_ {1} ^ {(1)} = 1 7 \mathrm{ksi}, \quad \sigma_ {2} ^ {(2)} = - 1 7 \mathrm{ksi}
$$
# Chapter 16
16.1 $[M] = \frac{\rho AL}{6}\left[ \begin{array}{ccc}2 & 1 & 0\\ 1 & 4 & 1\\ 0 & 1 & 2 \end{array} \right]$
16.2 a. $[M] = \frac{\rho AL}{2}\left[ \begin{array}{cccc}1 & 0 & 0 & 0\\ 0 & 2 & 0 & 0\\ 0 & 0 & 2 & 0\\ 0 & 0 & 0 & 1 \end{array} \right]$
$\mathbf{b.}[M] = \frac{\rho AL}{6}\left[ \begin{array}{cccc}2 & 1 & 0 & 0\\ 1 & 4 & 1 & 0\\ 0 & 1 & 4 & 1\\ 0 & 0 & 1 & 2 \end{array} \right]$
16.3 $\omega_{1} = 0.806\sqrt{u},\omega_{2} = 2.81\sqrt{\mu}$
16.4 $\omega_{1} = 5.368\times 10^{3}\mathrm{rad / s},\quad \omega_{2} = 17.556\times 10^{3}\mathrm{rad / s}$
16.5 a. $t(\mathrm{s})$ $d_{i}(\mathrm{ft})$ $\dot{d}_i(\mathrm{ft / s})$ $\ddot{d}_i(\mathrm{ft / s^2})$
<table><tr><td>0</td><td>0</td><td>0</td><td>25</td></tr><tr><td>0.03</td><td>0.01125</td><td>0.71</td><td>22.09</td></tr><tr><td>0.06</td><td>0.04238</td><td>1.03</td><td>-0.715</td></tr><tr><td>0.09</td><td>0.07287</td><td>0.67</td><td>-22.87</td></tr><tr><td>0.12</td><td>0.08278</td><td>-0.35</td><td>-45.28</td></tr><tr><td>0.15</td><td>0.05194</td><td>-1.43</td><td>-26.94</td></tr></table>
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16.6 a. t ðsÞ $d _ { i }$ ðftÞ $\dot { d } _ { i } \left( \mathrm { f t } / \mathrm { s } \right)$ $\ddot { d } _ { i } \ ( \mathrm { f t } / \mathrm { s } ^ { 2 } )$
<table><tr><td>0</td><td>0</td><td>0</td><td>10.00</td></tr><tr><td>0.02</td><td>0.0020</td><td>0.168</td><td>6.80</td></tr><tr><td>0.04</td><td>0.00672</td><td>0.256</td><td>1.968</td></tr><tr><td>0.06</td><td>0.01223</td><td>0.242</td><td>-3.338</td></tr><tr><td>0.08</td><td>0.01640</td><td>0.130</td><td>-7.84</td></tr><tr><td>0.10</td><td>0.01743</td><td>-0.053</td><td>-10.46</td></tr></table>
<table><tr><td>b. $t$ (s)</td><td> $d_{i}$ (ft)</td><td> $\dot{d}_{i}$ (ft/s)</td><td> $\ddot{d}_{i}$ (ft/s2)</td><td> $F(t)$ (lb)</td></tr><tr><td>0.00</td><td>0.00000</td><td>0.000</td><td>10.000</td><td>20.0</td></tr><tr><td>0.02</td><td>0.00179</td><td>0.169</td><td>6.923</td><td>16.0</td></tr><tr><td>0.04</td><td>0.00625</td><td>0.263</td><td>2.248</td><td>12.0</td></tr><tr><td>0.06</td><td>0.0115</td><td>0.254</td><td>-2.945</td><td>8.0</td></tr><tr><td>0.08</td><td>0.0157</td><td>0.150</td><td>-7.458</td><td>4.0</td></tr><tr><td>0.10</td><td>0.0169</td><td>-0.0147</td><td>-10.251</td><td>0.0</td></tr></table>
16.7 Node t ðsÞ di ðin:Þ $\dot { d } _ { i } \ ( \mathrm { i n . / s } )$ $\ddot { d } _ { i } \ ( \mathrm { i n } . / \mathrm { s } ^ { 2 } )$
<table><tr><td>2</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td></td><td>0.00025</td><td>2.6E-6</td><td>0.031</td><td>249.6</td></tr><tr><td></td><td>0.00050</td><td>3.4E-5</td><td>0.284</td><td>1768.9</td></tr><tr><td></td><td>0.00075</td><td>1.9E-4</td><td>1.085</td><td>4641.9</td></tr><tr><td></td><td>0.0010</td><td>6.36E-4</td><td>2.605</td><td>7519.3</td></tr><tr><td>3</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td></td><td>0.00025</td><td>6.59E-5</td><td>0.791</td><td>6328.8</td></tr><tr><td></td><td>0.00050</td><td>4.99E-4</td><td>2.817</td><td>9881.2</td></tr><tr><td></td><td>0.00075</td><td>1.51E-3</td><td>5.265</td><td>9701.7</td></tr><tr><td></td><td>0.0010</td><td>3.10E-3</td><td>7.369</td><td>7128.3</td></tr></table>
16.8 Using Newmarks method with $\begin{array} { r } { \gamma = \frac { 1 } { 2 } , \beta = \frac { 1 } { 6 } } \end{array}$
<table><tr><td>Node</td><td>t (s)</td><td> $d_i$ (in.)</td><td> $\dot{d}_i$ (in./s)</td><td> $\ddot{d}_i$ (in./s2)</td><td>F(t) (lb)</td></tr><tr><td rowspan="3">2</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>0.05</td><td>0.00172</td><td>0.103</td><td>4.131</td><td>0</td></tr><tr><td>0.10</td><td>0.01544</td><td>0.513</td><td>12.27</td><td>0</td></tr><tr><td rowspan="3">3</td><td>0</td><td>0</td><td>0</td><td>40.0</td><td>2000</td></tr><tr><td>0.05</td><td>0.0448</td><td>1.685</td><td>27.39</td><td>1800</td></tr><tr><td>0.10</td><td>0.1536</td><td>2.479</td><td>4.37</td><td>1600</td></tr></table>
$\begin{array} { l l l } { { { \bf 1 6 . 1 1 } } } & { { { \bf a . } { \ \omega } \omega _ { 1 } = \displaystyle \frac { 3 . 1 5 } { L ^ { 2 } } \left( \frac { E I } { \rho A } \right) ^ { 1 / 2 } , } } & { { \omega _ { 2 } = \displaystyle \frac { 1 6 . 2 4 } { L ^ { 2 } } \left( \frac { E I } { \rho A } \right) ^ { 1 / 2 } , } } & { { { \bf c . } { \omega } \omega _ { 1 } = \displaystyle \frac { 9 . 8 } { L ^ { 2 } } \left( \frac { E I } { \rho A } \right) ^ { 1 / 2 } } } \\ { { } } & { { { \bf d . } { \omega } = \displaystyle \frac { 1 4 . 8 } { L ^ { 2 } } \left( \frac { E I } { \rho A } \right) ^ { 1 / 2 } } } & { { } } & { { { \bf d . } } } \end{array}$ EI 1=2 EI 1=2 EI 1=2
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<table><tr><td rowspan="13">16.17</td><td colspan="2">Node:</td><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td></tr><tr><td>i</td><td>t (s)</td><td></td><td></td><td colspan="2">Temperature (°C)</td><td></td><td></td></tr><tr><td>0</td><td>0</td><td>200</td><td>200</td><td>200</td><td>200</td><td>200</td><td>200</td></tr><tr><td>1</td><td>8</td><td>0</td><td>159.0095</td><td>191.4441</td><td>198.2110</td><td>199.6110</td><td>199.8444</td></tr><tr><td>2</td><td>16</td><td>0</td><td>135.5852</td><td>178.1491</td><td>193.6620</td><td>198.2112</td><td>199.1445</td></tr><tr><td>3</td><td>24</td><td>0</td><td>120.2309</td><td>165.7003</td><td>187.3485</td><td>195.5379</td><td>197.5152</td></tr><tr><td>4</td><td>32</td><td>0</td><td>109.1993</td><td>154.9587</td><td>180.4038</td><td>191.7446</td><td>194.8115</td></tr><tr><td>5</td><td>40</td><td>0</td><td>100.7600</td><td>145.7784</td><td>173.4129</td><td>187.1268</td><td>191.1242</td></tr><tr><td>6</td><td>48</td><td>0</td><td>94.00311</td><td>137.8529</td><td>166.6182</td><td>181.9599</td><td>186.6590</td></tr><tr><td>7</td><td>56</td><td>0</td><td>88.39929</td><td>130.9034</td><td>160.1012</td><td>176.4598</td><td>181.6395</td></tr><tr><td>8</td><td>64</td><td>0</td><td>83.61745</td><td>124.7101</td><td>153.8759</td><td>170.7856</td><td>176.2620</td></tr><tr><td>9</td><td>72</td><td>0</td><td>79.43935</td><td>119.1075</td><td>147.9316</td><td>165.0508</td><td>170.6822</td></tr><tr><td>10</td><td>80</td><td>0</td><td>75.71603</td><td>113.9733</td><td>142.2502</td><td>159.3352</td><td>165.0171</td></tr></table>
<table><tr><td colspan="5">16.18</td></tr><tr><td rowspan="2">Time (s)</td><td rowspan="2">1</td><td colspan="2">Node</td><td rowspan="2">(using consistent capacitance matrix)</td></tr><tr><td>2</td><td>3</td></tr><tr><td colspan="5">Temperature (°C)</td></tr><tr><td>0</td><td>25</td><td>25</td><td>25</td><td></td></tr><tr><td>0.1</td><td>85</td><td>18.53611</td><td>26.36189</td><td></td></tr><tr><td>0.2</td><td>85</td><td>29.61303</td><td>21.63526</td><td></td></tr><tr><td>0.3</td><td>85</td><td>36.18435</td><td>22.42717</td><td></td></tr><tr><td>0.4</td><td>85</td><td>40.72491</td><td>25.30428</td><td></td></tr><tr><td>0.5</td><td>85</td><td>44.27834</td><td>28.85201</td><td></td></tr><tr><td>0.6</td><td>85</td><td>47.29072</td><td>32.49614</td><td></td></tr><tr><td>0.7</td><td>85</td><td>49.95809</td><td>36.01157</td><td></td></tr><tr><td>0.8</td><td>85</td><td>52.37152</td><td>39.31761</td><td></td></tr><tr><td>0.9</td><td>85</td><td>54.57756</td><td>42.39278</td><td></td></tr></table>
<table><tr><td colspan="5">16.18</td></tr><tr><td rowspan="2">Time (s)</td><td rowspan="2">1</td><td colspan="2">Node</td><td rowspan="2">(using consistent capacitance matrix)</td></tr><tr><td>2</td><td>3</td></tr><tr><td colspan="5">Temperature (°C)</td></tr><tr><td>1</td><td>85</td><td>56.60353</td><td>45.23933</td><td></td></tr><tr><td>1.1</td><td>85</td><td>58.46814</td><td>47.86852</td><td></td></tr><tr><td>1.2</td><td>85</td><td>60.1859</td><td>50.29457</td><td></td></tr><tr><td>1.3</td><td>85</td><td>61.76908</td><td>52.53218</td><td></td></tr><tr><td>1.4</td><td>85</td><td>63.22852</td><td>54.59557</td><td></td></tr><tr><td>1.5</td><td>85</td><td>64.574</td><td>56.49814</td><td></td></tr><tr><td>1.6</td><td>85</td><td>65.81448</td><td>58.25235</td><td></td></tr><tr><td>1.7</td><td>85</td><td>66.95818</td><td>59.86974</td><td></td></tr></table>
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16.18
<table><tr><td rowspan="2">Time (s)</td><td colspan="3">Node</td></tr><tr><td>1</td><td>2</td><td>3</td></tr><tr><td></td><td colspan="3">Temperature (°C)</td></tr><tr><td>0</td><td>25</td><td>25</td><td>25</td></tr><tr><td>1.8</td><td>85</td><td>68.01265</td><td>61.36096</td></tr><tr><td>1.9</td><td>85</td><td>68.98485</td><td>62.73586</td></tr><tr><td>2</td><td>85</td><td>69.88121</td><td>64.0035</td></tr><tr><td>2.1</td><td>85</td><td>70.70765</td><td>65.17226</td></tr><tr><td>2.2</td><td>85</td><td>71.46961</td><td>66.24984</td></tr><tr><td>2.3</td><td>85</td><td>72.17214</td><td>67.24336</td></tr><tr><td>2.4</td><td>85</td><td>72.81986</td><td>68.15938</td></tr><tr><td>2.5</td><td>85</td><td>73.41705</td><td>69.00393</td></tr><tr><td>2.6</td><td>85</td><td>73.96766</td><td>69.78261</td></tr><tr><td>2.7</td><td>85</td><td>74.47531</td><td>70.50053</td></tr><tr><td>2.8</td><td>85</td><td>74.94336</td><td>71.16246</td></tr><tr><td>2.9</td><td>85</td><td>75.3749</td><td>71.77274</td></tr><tr><td>3</td><td>85</td><td>75.77277</td><td>72.33542</td></tr></table>
# Appendix A
A1. a. $\left[ { \begin{array} { r r } { 3 } & { 0 } \\ { - 3 } & { 1 2 } \end{array} } \right]$ b. Nonsense c. Nonsense
$\left\{ { \begin{array} { l } { 1 1 } \\ { 9 } \\ { 1 1 } \end{array} } \right\}$ e. Nonsense f. $\left[ { \begin{array} { r r r } { 1 0 } & { 7 } & { 6 } \\ { 3 } & { - 1 } & { 7 } \end{array} } \right]$
$\left[ \begin{array} { l l } { 1 } & { 0 } \\ { { \frac { 1 } { 4 } } } & { { \frac { 1 } { 4 } } } \end{array} \right]$
A3. ${ \frac { 1 } { 1 7 } } \left[ { \begin{array} { r r r } { 1 2 } & { - 3 } & { - 8 } \\ { - 3 } & { 5 } & { 2 } \\ { - 8 } & { 2 } & { 1 1 } \end{array} } \right]$
A4. Nonsense
A5. $\left[ \begin{array} { l l } { { \frac { 1 } { 2 } } } & { 0 } \\ { { \frac { 1 } { 8 } } } & { { \frac { 1 } { 8 } } } \end{array} \right]$
A6. Same as A3
A8. $\left[ \begin{array} { c c } { \cos \theta } & { - \sin \theta } \\ { \sin \theta } & { \cos \theta } \end{array} \right]$
# Appendix B
B1. $x _ { 1 } = 3 . 1 5 , x _ { 2 } = 0 . 6 2$
B2. $x _ { 1 } = 3 . 1 5 , x _ { 2 } = 0 . 6 2$
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B3. $x_{1} = 2.5, x_{2} = -1, x_{3} = 0.5$
B4. $x_{1} = 3, x_{2} = -1, x_{3} = -2$
B5. a. $\left\{ \begin{array}{l}x_{1}\\ x_{2} \end{array} \right\} = \left[ \begin{array}{ll}2 & -1\\ 1 & -1 \end{array} \right]\left\{ \begin{array}{l}y_{1}\\ y_{2} \end{array} \right\}$ b. $\left\{ \begin{array}{l}z_1\\ z_2 \end{array} \right\} = \left[ \begin{array}{ll} - 3 & 2\\ 5 & -3 \end{array} \right]\left\{ \begin{array}{l}y_{1}\\ y_{2} \end{array} \right\}$
B6. $x_{1} = 0, x_{2} = 1, x_{3} = 2, x_{4} = 2, x_{5} = 0$
B7. $x_{1} = 3.15, x_{2} = 0.62$
B8. a. Unique b. Nonexistent c. Unique d. Nonunique
# Appendix D
D1. a. $f_{1y} = f_{2y} = -5 \mathrm{kip}$ , $m_{1} = -m_{2} = -100 \mathrm{k-ft}$
b. $f_{1v} = f_{2v} = -5 \mathrm{kip}, \quad m_1 = -m_2 = -18.75 \mathrm{k-ft}$
c. $f_{1y} = f_{2y} = -15 \mathrm{kip}, \quad m_1 = -m_2 = -75 \mathrm{k-ft}$
d. $f_{1v} = -18.75 \text{ kip}, \quad f_{2v} = -6.25 \text{ kip}, \quad m_1 = -58.3 \text{ k-ft}, \quad m_2 = 33.3 \text{ k-ft}$
e. $f_{1v} = -6$ kip, $f_{2v} = -14$ kip, $m_{1} = -26.67$ k-ft, $m_{2} = 40$ k-ft
f. $f_{1y} = -0.99 \, kN$ , $f_{2y} = -4.0 \, kN$ , $m_{1} = -2.04 \, kN \cdot m$ , $m_{2} = 5.10 \, kN \cdot m$
g. $f_{1y} = f_{2y} = -6 \, kN$ , $m_{1} = -m_{2} = -7.5 \, kN \cdot m$
h. $f_{1y} = f_{2y} = -10 \, kN$ , $m_{1} = -m_{2} = -6.67 \, kN \cdot m$
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# Index
# A
Adaptive refinement, 355
Adjoint method, 718
Admissible variation, 55
Aluminum shapes, properties of, 759772
Amplitude, defined, 649
Approximation functions, 7274
compatible, 73
complete, 7374
conforming, 73
displacement, 7274
interpolation, 74
Aspect ratio (AR), 351, 352353
Axial symmetry, 100
Axis of revolution, 412
Axis of symmetry, 412
Axisymmetric element, 9, 412442, 684685
applications of, 428433
body forces, 419420
consistent-mass matrix, 684685
defined, 9, 412
discretization, 423
displacement functions, 415417
element type, selection of, 415
equations, 419421
introduction to, 412
pressure vessel, solution of, 422428
sti¤ness matrix, 412422, 423428
strain/displacement relationships, 417419
stress/strain relationships, 417419
surface forces, 420421
# B
Banded-symmetric method, 735741
Bar elements, 6772, 92100, 109120, 120124, 124127, 127131, 444449, 665669, 669674. See also Truss equations
analysis of, 665669, 669674
collocation method, 129
consistent-mass matrix, 651653
displacement function, 68, 446, 650
dynamic analysis of, 649653, 665669, 669674
equations, 124127, 447449, 649653
exact solution, 120124
finite element solution, 120124
Galerkins residual method, 124127, 131
isoparametric formulation, 444449
least squares method, 130
local coordinates for, 6672
lumped-mass matrix, 651
mass matrix, 650653
natural frequencies, 665669
one-dimensional problems, 127131, 665669, 669674
potential energy approach, 109120
residual methods, 124127, 127131
selection of, 67, 444446, 650
sti¤ness matrix, 6672, 92100, 444449, 650653
strain/displacement relationships, 69, 446447, 650
stress, computation of, 8283
stress/strain relationships, 69, 446447, 650
subdomain method, 129130
three-dimensional space, 92100
time-dependent (dynamic) stress analysis, 649653
time-dependent problem, 669674
transformation matrix, 92100
Beam element, 152161, 161163, 194199, 214218, 218236, 255269, 674681
arbitrarily oriented, 214218, 255269
bending, 153158, 255260
boundary conditions, 161163
defined, 152
deformations, 153158
displacement function, 155156
equations, 157158, 161163
mass matrices, 674681
natural frequencies, 674681
nodal hinge, 194199
rigid plane frames, 218236
selection of, 154
shape functions, 155156
sign conventions, 152, 256257
space, arbitrarily oriented in, 255269
sti¤ness, 152161
sti¤ness matrix, 153158, 158161
strain/displacement relationships, 156157
stress/strain relationships, 156157
transformation matrix, 216, 259260
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Beam element (Continued )
transverse shear deformations, 158161
two-dimensional, arbitrarily oriented, 214218
Beam equations, 151213
bending deformations, 153158
boundary conditions, 161163
direct sti¤ness method, 163175
displacement functions, 155156
distributed loading, 175188
Euler-Bernouli theory, 153158
exact solution, 188194
finite element solution, 188194
fixed-end reactions, 175
Galerkins method, 201203
introduction to, 151152
load replacement, 177178
nodal hinge, element with a, 194199
potential energy approach, 199201
sign conventions, 152
sti¤ness matrix, 153158, 158161, 161163
sti¤ness of element, 152161
strain/displacement relationships, 156157
stress/strain relationships, 156157
Timoshenko theory, 158161
transverse shear deformations, 158161
work-equivalence method, 176177
Bending, 153158, 255260, 514518
beam elements in arbitrary space, 255260
deformations in beam elements, 153158
plate element, 514518
rigidity of a plate, 517
Body forces, 324326, 419420, 448, 460, 497498
axisymmetric elements, 419420
bar element, 448
centrifugal, 325
natural coordinate system, 448
plane element, 460
tetrahedral element, 497498
treatment of, 324326
Boundary conditions, 1314, 34, 3952, 103109, 161163, 320322, 601
beam elements, 161163
constant-strain triangular (CST) element, 320322
fluid flow, 601
homogeneous, 3940
inclined supports, 103109
introduction to, 1314, 34
nonhomogeneous, 39, 4041
penalty method, 5052
skewed supports, 103109
sti¤ness method, 3952
#
Castiglianos theorem, 12
Central di¤erence method, 653, 654659
Centrifugal body force, 325
Circular frequency, natural, 649
Coarse-mesh generation, 310
Coe‰cient matrix, inversion of, 726
Coe‰cient of thermal expansion, 618
Cofactor method, 716717
Collocation method, 129
Column matrices, 4, 708
Compatibility, 35, 363367, 746748
condition of, 748
equations, 746748
finite element results, 363367
requirement, 35
Compatible displacements, 755
Compatible functions, 73
Complete, approximation functions, 7374
Computer programs, 67, 2324, 374380, 524528, 693701
finite element method, 2324
plate bending element, solution for, 524528
role of, 67
step-by-step solutions, 374380
structural dynamics, 693701
Concentrated loads, 360361
Condensation, see Static condensation
Conduction,535538,542546,557558
element conduction matrix, 542546, 557558
heat, one-dimensional, 535537
heat, two-dimensional, 537538
Conforming functions, 73
Connecting (mixing) di¤erent kinds of elements, 361362
Consistent-mass matrix, 651653, 682685
Constant-strain triangular (CST) element, 304305, 310324, 324329, 342, 406408
body forces, 324326
boundary conditions, 320322
coarse-mesh generation, 310 defects, 342
displacement function, 311315
equations, 310324
forces (stresses), 322324
global equations, 320322
introduction to, 304305
LST elements, comparison of, 406408
matrix, 310324, 329331
nodal displacements, 322
penalty formulation, 331
selection of, 310311
strain/displacement relationships, 315320
stress/strain relationships, 315320
surface forces, 326329
Constitutive law, 11
Constitutive matrix, 309, 522
Continuity, 35, 73
requirement, 35 symbol, 73
Convection, heat transfer with, 538539, 540
Convergence of finite element solution, 367368
Coordinates, 6672, 444446
bar elements, 6772, 444446
intrinsic system, 444 natural system, 444
Coulomb-Mohr theory, 342
Cramers rule, 724725
CST, see Constant-strain triangular (CST) element
Cubic elements, 9
Curvature matrix, 521522
# D
DAlemberts principle, 755756
Defects, CST elements, 342
Deformation, 33, 153158, 158161, 514518
bending in beams, 153158
bending rigidity of a plate, 517 defined, 33
Kirchho¤ assumptions, 515516
plate bending, 514518
potential energy, 518
stress/strain relationships, 517518
transverse shear in beams, 158161
Degrees of freedom, 14, 15, 29 defined, 15
spring element, 29
unknown, 14
Determinant, defined, 716
Di¤erential equations, 535538, 594596, 744746
elasticity theory, 744746
equilibrium, 744746
fluid flow, 594598
heat transfer, 535538
Direct equilibrium method, 11
Direct integration, 653
Direct sti¤ness method, 24, 1314, 28, 3739, 163175.
See also Superposition
beam analysis using, 163175
history of, 24, 28
total sti¤ness matrix, assembly by, 3739
use of, 1314
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Direction cosines, 85, 9596
Directional sti¤ness bias, 371
Discontinuities, natural subdivisions at, 354, 357
Discretization, 1, 810, 331332, 423 axisymmetric element, 423
finite element method, 1, 810, 331332
plane stress, 331332
Displacement function, 11, 3132, 68, 155156, 311315, 399401, 446, 450451, 455456, 494496, 519521
bar element, 68, 446
beam element, 155156
constant-strain triangular (CST) element, 311315
Hermite cubic interpolation, 155156
interpolation, 32
isoparametric function, 446, 450451, 455456
linear-strain triangle (LST), 399401
plane element, 455456
plane stress element, 450451
plate bending element, 519521
selection of, 11
shape, 32, 155156
spring element, 3132
tetrahedral element, 494496
Displacement method, 7, 2864. See also Sti¤ness method introduction to, 2864 use of, 7
Displacements, 34, 70, 7274, 755758. See also Strain/ displacement relationships
approximation functions for, 7274
compatible, 755
nodal, 34, 70
virtual work, principles of, 755758
Distributed loading, 175188 beams, 175188
e¤ective global nodal forces, 181182
fixed-end reactions, 175
general formulation of, 178179
load replacement, 177178
work-equivalence method, 176177
Dynamics, 647707
axisymmetric element, analysis of, 684685
bar element equations, 649653
beam element mass matrices, 674681
central di¤erence method, 653, 654659
computer program example solutions, 693701
introduction to, 647
mass matrices, 650653, 674681, 681685
natural frequencies, 649, 665669, 674681
Newmarks method, 659663
numerical integration in time, 653665, 687693
one-dimensional bar analysis, 665669, 669674
plane frame element, analysis of, 682683
plane stress/strain element, analysis of, 683684
spring-mass system, 647649
structural, 647707
tetrahedral (solid) element mass matrices, analysis of, 685
time, numerical integration in, 653665, 687693
time-dependent heat transfer, 686693
time-dependent stress analysis, 649653, 669674
truss element, analysis of, 681682
Wilsons (Wilson-Theta) method, 664665
# E
E¤ective stress, 341
Elasticity theory, 744751
compatibility equations, 746748
condition of compatibility, 748
di¤erential equations of equilibrium, 744746
equilibrium, di¤erential equations of, 744746
introduction to, 744
modulus of elasticity, 748
strain/displacement, 746748
stress/strain relationships, 748751
Elements, 810, 11, 1314, 3034, 65150, 151213, 304305, 310324, 342, 351362, 398403, 444449, 449452, 480482, 493500, 501508, 514533
aspect ratio (AR), 351
axisymmetric, 9
bar, 65150, 444449
beam, 151213
coarse-mesh generation, 310
connecting (mixing), modeling, 361362
constant-strain triangular (CST), 304305, 310324, 342
cubic, 9
defects, CST, 324
equations, 11, 1314, 34, 6970, 402403, 451452, 522523
finite, 8
forces, 34, 70
heterosis, 523
isoparametric, 446
LaGrange, 482
linear hexahedral, 501504
linear-strain triangle (LST), 398403
plane stress, 449452
plate bending, 514533
Q8, 480
Q9, 482
quadratic, 9
quadratic hexahedral, 504508
refinement, methods of, 355356, 358359
selection of, 810, 3031, 310311, 399, 444446, 449, 519
serendipity, 481
shapes, modeling, 351
sizing, 355356, 358359
spring, 3034
sti¤ness matrix, 11, 3334, 6672, 402403, 447449, 451452, 522523
tetrahedral, 493500
transition triangles, 359360
Energy method, 12
Equations, 11, 1314, 34, 5260, 65149, 151213, 214237, 238255, 310324, 398411, 419422, 447449, 451452, 459460, 497498, 522523, 535538, 542546, 557558, 594596, 599601, 608, 659661, 664665, 722743, 744751.
See also Elasticity theory;
Simultaneous linear equations
axisymmetric element, 419422
bar element, 124127, 447449
beam, 151213
beam element, 199201, 201203
compatibility, 746748
constant-strain triangular (CST) element, 310324
di¤erential, 535538, 594596, 744745
element, 11, 1314, 6970
element conduction, 542546, 557558
finite element, 111
fluid flow, 599601, 608
frame, 214237
global, 1314, 34, 70, 161163, 546, 601
grid, 214, 238255
heat transfer, 535538
isoparametric formulation, 447449, 459460
Jacobian function, 447
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Equations (Continued )
linear-strain triangle (LST), 398411
Newmarks, 659661
one-dimensional, 124127, 131, 542546
plane element, 459460
plane stress element, 451452
plate bending element, 522523
simultaneous linear, 722743
spring element, 5260
tetrahedral element, 497498
total, 1314, 70
truss, 65149
two-dimensional, 557558
Wilsons, 664665
Equilibrium, 363367, 744746
compatibility and, 363367
di¤erential equations 744746
finite element results, 363367
Equivalent stress, 341
Euler-Bernouli theory, 153158
Exact solution, 120124, 188194
bar element, 120124
beams, 188194
finite element solution, comparison to, 120124, 188194
Explicit numerical integration method, 689
F
Field problems, 52
Finite element, defined, 8
Finite element method, 126, 120124, 350363, 540555, 555564, 566568, 569574, 598606, 606610. See also Modeling
advantages of, 1922
applications of, 1519
boundary conditions, 1314
computer, role of, 67
computer programs for, 2324
constitutive law, 11
defined, 1, 8
degrees of freedom, 14, 15
direct equilibrium method, 11
direct sti¤ness method, 23, 1314
discretization, 1, 810
displacement function, selection of, 11
displacement method, 7
element conduction matrix, 542546, 557558
element types, selection of, 810, 541, 555, 598
energy method, 12
exact solution, comparison to, 120124
flexibility method, 7
fluid flow, 598606, 606610
force method, 7
functional, 12
generalized displacements, 14
global equations, 1314
gradient/potential relationship, 599, 607
heat flux/temperature gradient relationship, 542, 556557
heat transfer, 540555, 555564, 566568, 569574
history of, 24
introduction to, 126
matrix notation, 46
modeling, 350363
one-dimensional, 540555, 569, 598606
potential function, 598599, 607
primary unknowns, 14
results, interpretation of, 14
steps of, 714
sti¤ness method, 7
strain/displacement relationships, 11
stress/strain relationships, 11, 14
temperature function, 541, 556
temperature gradient/temperature relationships, 542, 556557
three-dimensional, 566568
total equations, 1314
truss equations, 120124
two-dimensional, 555564, 606610
variational method, 540555
velocity/gradient relationship, 599, 607
weighted residuals, methods of, 1213
work method, 12
Finite element solution, 120124, 188194, 331342, 363367, 367369
approximations in, 364367
bar element, 120124
beams, 188194
compatibility of results, 363367
convergence of, 367368
CST defects, 342
discretization, 331332
equilibrium of results, 363367
exact solution, comparison to, 120124, 188194
plane stress, 305309
sti¤ness matrix, assemblage of, 332342
Fixed-end forces, 229230
Fixed-end reactions, 175
Flexibility method, 7
Flowcharts, 374, 574, 611, 656, 661
central di¤erence method, 656
fluid flow, 611
heat transfer, 574
Newmarks equations, 661
numerical integration, 656
plane stress/strain, 374
Fluid flow, 593616
boundary conditions, 601
di¤erential equations, 594598
equations, 599601, 608
finite element formulation, 598606, 606610
flowchart for, 611
global equations, 601
gradient/potential relationship, 599, 607
introduction to, 593
nodal potentials, 601
one-dimensional, 598601
pipes, 596598
porous medium, 594596
potential function, 589
program, example of, 611612
solid bodies, around, 596598
sti¤ness matrix, 599601, 608
two-dimensional, 606610
velocities, 602
velocity/gradient relationship, 599, 607
volumetric flow rates, 602
Force, 7, 34, 36, 70, 178182, 229230, 232233, 322324, 324329, 419421, 448449, 460, 497498, 752754
axisymmetric elements, 419421
bar element, 70, 448449
body, 324326, 419420, 448, 460, 497498
centrifugal body, 325
constant-strain triangular (CST)
element, 322324, 324329
equivalent nodal, 178180, 752754
fixed-end, 229230
global nodal matrix, 36
method, 7
nodal, 178182, 232233
plane element, 460
rigid plane frames, 229230, 232233
spring element, 34
stresses, 322324
surface, 326329, 420421, 448449, 460, 498
tetrahedral element, 497498
Forced convection, 538, 540
Frame equations, 214237
e¤ective nodal forces, 232233
fixed-end forces, 229230
inclined supports, 237
introduction to, 214
rigid plane frames, 218236
skewed supports, 237