Effects of Long-Term Creep on the Integrity of Modern Wood Structures

Files
etd.pdf (1.06 MB)
Downloads: 440
TR Number
Date
1996-12-10
Journal Title
Journal ISSN
Volume Title
Publisher
Virginia Tech
Abstract

Short-term creep tests in tension and in compression were conducted on southern pine, Douglas-fir, yellow-poplar, and Parallam™ samples at temperatures ranging between 20 and 80° C and at 6, 9 and 12% moisture content. The principle of time-temperature superposition was applied to form a master curve that extended for a maximum of 2 years. The horizontal shift factors followed an Arrhenius relation with activation energies ranging between 75 and 130 kJ/mole. It was not possible to superpose the compliance curves at 70 and 80° C, this is attributed to the presence of multiple components in wood with different temperature dependence.

Long-term creep tests were also conducted in tension and in compression at 20° C and 12% moisture content for over 2 years. The resulting compliance curves were fitted to the power law equation using a nonlinear fitting procedure. The results were compared with those of the short-term creep tests.

Finite element analysis was conducted on selected wood structures to determine the effect of creep on serviceability and stability.

Description
Keywords
Finite element method, structures, Wood, creep, TTSP
Citation