剪切断裂经常发生在承受横向载荷的木梁和面板中。在高温下,木材将经历复杂的物理和化学过程，显著影响剪切性能。在本文中,具有三个不同剪切平面的v缺口道格拉斯冷杉标本：（a）径向切向（RT）；（b）径向纵向（RL），和(C)纵向径向(LR)，在20°C至180°C的高温下制造和测试。数字图像相关（DIC）技术用于测量剪切应变。发现剪切平面对破坏模式有显着影响，剪切强度,和剪切模量。剪切强度和剪切模量一般随温度的升高而降低。然而,当干木质素的硬化发生在100°C和140°C之间时,剪切强度显著提高。此外，欧洲规范5中剪切强度的设计曲线对于所有具有不同剪切平面的试样都是保守的。
Shear fracture frequently occurs in timber beams and panels subjected to transverse loads. At elevated temperatures, wood will undergo complex physical and chemical processes which significantly affect the shear properties. In this paper, the v-notched Douglas-fir specimens with three different shear planes: (a) Radial-Tangential (RT); (b) Radial-Longitudinal (RL), and (c) Longitudinal-Radial (LR), were fabricated and tested under the elevated temperatures from 20 °C to 180 °C. The digital image correlation (DIC) technique was used to measure the shear strain. It was found that the shear plane had a significant effect on the failure modes, shear strength, and shear modulus. The shear strength and shear modulus generally decreased with the increase of temperature. However, the shear strength was significantly improved when the hardening of the dry lignin occurred between 100 °C and 140 °C. Moreover, the design curve for the shear strength in Eurocode 5 is conservative for all the specimens with different shear planes.
