多模微波场中玄武岩加热及内部损伤机理研究  

Research on heating characteristics and internal damage emergence of basalt in multimode microwave field

作　　者：邵珠山 吴丹丹[1,2] 袁媛 费心爽[2,3] 郭轩 SHAO Zhushan;WU Dandan;YUAN Yuan;FEI Xinshuang;GUO Xuan(College of Science,Xi’an University of Architecture and Technology,710055 Xi’an,China;Shaanxi Key Laboratory for Geotechnical and Underground Space Engineering,Xi’an University of Architecture and Technology,710055 Xi’an,China;College of Civil Engineering,Xi’an University of Architecture and Technology,710055 Xi’an,China)

机构地区：[1]西安建筑科技大学理学院,西安710055 [2]西安建筑科技大学陕西省岩土与地下空间工程重点试验室,西安710055 [3]西安建筑科技大学土木工程学院,西安710055

出　　处：《应用力学学报》2022年第1期129-136,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金面上项目资助(No.11872287);陕西省重点研发计划资助项目(No.2019ZDLGY01-10)。

摘　　要：随着微波加热技术的兴起,该技术被广泛应用于岩石破碎中。借助玄武岩研究了微波场中岩石内部温度场和应力场的分布规律,分析了岩石内部损伤机理。采用试验常用频率的工业微波炉对玄武岩试样进行微波照射,利用SEM分析微波照射前后岩石试样内部微裂纹演化规律;结合COMSOL 5.5建立岩石均匀模型分析微波场中岩石表面升温速率,建立岩石二相矿物模型对岩石内部温度、温度梯度和热应力分布进行分析,通过温度场和应力场评价微波加热对岩石造成的损伤。结果表明:在微波场中,同一功率水平下岩石表面升温速率先增大、后减小;SEM图像证实了微波照射能够加速岩石内部微裂纹扩展,强吸波性矿物在经过微波照射后熔融破坏;岩石均匀模型计算得到的上表面平均升温速率与微波加热结果基本吻合,岩石二相矿物模型计算得到的内部热应力在矿物分界面处达到最大值。试验结果证明了微波照射能够加速玄武岩热损伤和裂纹扩展。With the rise of microwave heating technology,this technology is widely used in rock crushing.In this paper,basalt is used to analyze the heating characteristics,temperature and thermal stress fields,and internal damage emergence of rock under multi-source microwave irradiation.Basalt samples were irradiated by industrial microwave oven with common experimental frequency.SEM was used to analyze the evolution law of microcracks in rock samples before and after microwave irradiation.Combined with COMSOL5.5,a rock uniform model was established to analyze the heating rate of rock surface in microwave field.A rock two-phase mineral model was established to analyze the internal temperature,temperature gradient and thermal stress distribution of rock.The damage of rock caused by microwave heating was evaluated by temperature field and stress field.The results show that in the microwave field,the heating rate of rock surface increases at first and then decreases at the same power level.SEM images confirm that microwave irradiation can accelerate the propagation of microcracks in rock,and strong wave-absorbing minerals are melted and destroyed after microwave irradiation.The average heating rate of the upper surface calculated by the rock homogeneous model is consistent with the results of microwave heating,and the internal thermal stress calculated by the rock two-phase mineral model reaches the maximum at the mineral interface.The experimental results show that microwave irradiation can accelerate the thermal damage and crack propagation of basalt.

关 键 词：微波加热 升温速率 裂纹 损伤 数值模拟 热应力 

分 类 号：TU452[建筑科学—岩土工程]