Properties of Materials — Worked Examples

A construction-material specimen has mass $m=12.6\text{ kg}$ and bulk volume $V=0.00500\text{ m}^3$. Determine density and unit weight using $g=9.81\text{ m/s}^2$.

A porous specimen weighs $540\text{ g}$ before oven drying and $450\text{ g}$ after drying to the method-defined constant mass. Determine dry-basis moisture content.

A specimen has total bulk volume $0.0100\text{ m}^3$ and measured void volume $0.00200\text{ m}^3$. Determine porosity as a decimal and percentage.

A round steel tension specimen has diameter $12.5\text{ mm}$ and gauge length $50.0\text{ mm}$. In the linear-elastic range, a tensile force of $24.5\text{ kN}$ produces an elongation of $0.0500\text{ mm}$. Determine engineering stress, strain, and elastic modulus.

A $30.0\text{ m}$ steel element experiences a temperature increase of $35.0^\circ\text{C}$. Use $\alpha=11.7\times10^{-6}/^\circ\text{C}$. Determine its free thermal expansion.

A $2.00\text{ m}$ aluminum frame and adjacent glass edge both warm by $30.0^\circ\text{C}$. Use $\alpha_{Al}=23\times10^{-6}/^\circ\text{C}$ and $\alpha_g=9\times10^{-6}/^\circ\text{C}$. Determine their free differential movement.

A reference material has an accepted value of $100.0\text{ MPa}$. A laboratory reports five replicate results: 107.8, 108.1, 108.0, 107.9, and 108.2 MPa. Interpret the measurement system qualitatively.

A coastal pedestrian handrail can be fabricated from painted carbon steel, galvanized steel, stainless steel, or aluminum. Select the engineering comparison framework rather than choosing from tensile strength alone.