Composites often are able to carry more load after damage due to the structure of laminates. In addition, damage can be difficult to detect in composites compared to homogeneous materials. Understanding the behavior of composite material after damage is vital for composite structural design. Currently, experimental methods exist for classifying...
This paper offers a practical solution of the complicated equations
for the deflections of nonorthotropic plates; in this discussion
plywood plates made of Douglas fir are considered. The intricate
partial differential equations are expressed in terms of finite differences.
The simultaneous algebraic linear equations thus obtained
are easily solved.
The...
The compressive behavior of continuous fiber composites is not as well
understood as their tensile behavior because research and industrial applications have until
recently focused on the latter. Furthermore, most theoretical and experimental studies on
the compression of composites have examined the case of unidirectional specimens with
fibers along the...
The main objective of this study was to determine appropriate
accelerated aging methods for exterior plywood made with Southeast
Asian hardwood face veneers. A secondary objective of this study
was to determine the durability of exterior plywood made with keruing
(12 Dipterocarpus spp.).
To reach these objectives I made plywood...
Elastic properties of plywood panels are essential for predicting
structural behavior of wood systems. The ASTM Standard D 3043-76
which evaluates the moduli of elasticity (MOE) of plywood, treats
these panels as one dimensional beams instead of two-dimensional
plates, which results in an overestimate of the MOE. Improved procedures
for...
Current compression perpendicular-to-grain (c-perp) design values for wood members are based on mean stress using the ASTM D143 specimen. Base design value, as determined from 0.04-in deformation in the ASTM specimen, is applied to all c-perp applications. While the standard ASTM test was presumably believed to adequately reflect relevant c-perp...
Formaldehyde-based adhesives such as urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives dominate the current wood adhesive market. However, these adhesives are derived from petrochemicals and carcinogenic formaldehyde. In this study, we developed two formaldehyde-free adhesives based on abundant, renewable, and inexpensive soy flour (SF).
The first adhesive was mainly composed of...