The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock spe...The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the mechanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 C to 500 C, the internal stress and internal strain are weak; whereas above 500 C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fi re reduces the mechanical performance of granite signi fi cantly. Moreover, it is found that after 3 min of exposure to fi re,the mechanical energy necessary to fragment the granite can be reduced up to 80%.展开更多
文摘以实际工程中常用的钢管混凝土组合柱为研究对象,通过ABAQU S大型有限元软件模拟钢管混凝土组合柱在标准火和真实火中的截面温度分布、应力、变形、破坏形态、耐火极限等力学行为。其中标准火选用ISO-834标准火模型,真实火采用欧洲规范Eurocode 1 Part 1-2中的参数火模型来近似模拟真实火灾的温度—时间关系。研究发现,钢管混凝土柱在两种火场环境中的行为差异很大,真实火中的冷却过程对钢管混凝土的破坏起重要的影响。基于本研究,还初步得到火灾过程中环境温度的升温速度、柱火灾荷载比等对钢管混凝土组合柱的抗火性能的影响。
文摘The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the mechanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 C to 500 C, the internal stress and internal strain are weak; whereas above 500 C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fi re reduces the mechanical performance of granite signi fi cantly. Moreover, it is found that after 3 min of exposure to fi re,the mechanical energy necessary to fragment the granite can be reduced up to 80%.
