휨하중하에서 목재의 CREEP 거동에 관한 연구

Study on the creep behavior of wood under bending loads

Nonlinear Five-Element Model(N5-E) and Double Three-Integral Model(D3-Ⅰ)have been used successfully for creep prediction of nailed joints in previous researches. In this study, the same models were applied to solid wood in bending. To predict creep under long-term variable loads, three Solutions-shch as applications of 1) Modified Superposition Principle to recoverable creep and Strain Hardening Principle to nonrecoverable creep, 2) Modified Superposition Principle to total creep, and 3) Improved Modified Superposition Principle to total creep-have been incorporated into the models. The predictions of two models by three Solutions were compared with the results of variable load tests. As a result, two models and three Solutions predicted very close creep values to experimental data. However, the predictions of D3-Ⅰ for instantaneous deformations were somehat lower than those of experimental data.