Machine Stress Rated MSR Evaluated MEL Lumber

Overview

Engineering reference data for Machine Stress Rated MSR Evaluated MEL Lumber in material science and properties.

Key Formulas

Stress

$\sigma = \frac{F}{A}$

Force per unit area.

Strain

$\varepsilon = \frac{\Delta L}{L_0}$

Change in length per original length.

Hooke's Law

$\sigma = E \varepsilon$

Stress proportional to strain in elastic region.

Thermal Expansion

$\Delta L = \alpha L_0 \Delta T$

Length change due to temperature.

Variables

Symbol	Description	Unit
$\sigma$	Stress	Pa
$\varepsilon$	Strain	—
$E$	Young's modulus	Pa
$\alpha$	Thermal expansion coefficient	1/°C
$\Delta T$	Temperature change	°C

Mechanical Properties Data

MSR (Machine Stress Rated) and MEL (Machine Evaluated Lumber) grades with their allowable design values.

Design Value Definitions

• Fb: Allowable 10-year load duration bending stress parallel to grain.
• E: Modulus of elasticity.
• Ft: Allowable 10-year load duration tensile stress parallel to grain.
• Fc: Allowable 10-year load duration compressive stress parallel to grain.

Interactive Charts

References

• Original Source