Module 2 Worked Examples: Timber Tension and Compression Members

A timber tie carries $P=72\text{ kN}$ through a clear section measuring $100\text{ mm}\times180\text{ mm}$. Determine the axial tension stress.

A $120\text{ mm}$ wide by $50\text{ mm}$ thick timber plate has one $22\text{ mm}$ diameter hole crossing the critical section. Determine the simple projected net area used for the section check.

A beam reaction of $36\text{ kN}$ is carried by a $100\text{ mm}$ wide seat with a $120\text{ mm}$ bearing length. Determine the average bearing stress.

A rectangular timber post is $150\text{ mm}\times250\text{ mm}$, $3.0\text{ m}$ long, and has $K=1.0$. Determine $KL/d$ about both section dimensions.

For a column with governing $L_e/d=20$ and $E_{\min}'=4{,}000\text{ MPa}$, calculate $F_{cE}$.

Use $F_c^*=12.0\text{ MPa}$, $F_{cE}=8.22\text{ MPa}$, and $c=0.80$. Determine $C_P$ and $F_c'$.

A $150\text{ mm}\times250\text{ mm}$ post has $F_c'=6.60\text{ MPa}$. Determine the axial resistance corresponding to the stress check.

Keep $d=150\text{ mm}$ and $K=1.0$, but increase the unsupported length from $3.0\text{ m}$ to $4.5\text{ m}$. Compare slenderness.

Two equal-area conceptual posts are available: $150\times300\text{ mm}$ and $200\times225\text{ mm}$. With the same $K$ and $L$, identify which has the smaller governing $KL/d$.

A timber tie passes the clear-section tension check but uses a short two-row bolted end connection close to the member end. Identify the additional checks required before approval.

A $150\text{ mm}\times250\text{ mm}$ sawn-lumber column is $3.0\text{ m}$ long. Use $E_{min}'=4{,}000\text{ MPa}$ and $F_c^*=12\text{ MPa}$. Compare the weak-direction stability result using the NDS Appendix G recommended design $K_e$ values for commonly approximated ideal end conditions. For sawn lumber use $c=0.80$.