Apparent and True (shear-free) E
Technical Topic
The values typically published for modulus of elasticity (E) for most structural glued laminated timber (glulam) and most structural composite lumber, such as laminated veneer lumber (LVL), are the “apparent” E (Eapparent). Glulam and SCL manufacturers sometimes elect to publish shear-free modulus of elasticity values, which is commonly termed “true E” (Etrue).
This publication is designed for: architects, engineers, designers
This publication discusses the difference between Etrue and Eapparent. It also explains where the different types of E values are used, how to address them when designing, and how to make meaningful comparison between the two.
Key sections include:
Equation to convert between Etrue and Eapparent
Table of equivalent Etrue and Eapparent for glulam products
A more complete explanation of this issue is provided in APA's Technical Topic: True (shear-free) and Apparent Moduli of Elasticity, Form TT-082.
Published by APA — The Engineered Wood Association.
