为求解同时考虑时空耦合因素和松弛时间因素的高响应速度传热Green and Lindasy（GL）方程，设计了一个半无限长杆的一维GL导热问题，运用Laplace变换获得其解析解．通过比较无限长杆上短时间内的温度、应变、应力分布的解析解与数值仿...为求解同时考虑时空耦合因素和松弛时间因素的高响应速度传热Green and Lindasy（GL）方程，设计了一个半无限长杆的一维GL导热问题，运用Laplace变换获得其解析解．通过比较无限长杆上短时间内的温度、应变、应力分布的解析解与数值仿真结果，得出不考虑松弛时间的温度分布的最大偏差不超过10K，应变和应力分布的最大偏差为5％。依据此结论，在应用GL模型研究高温燃气加热铝质活塞的低周热疲劳问题时，可以忽略松弛时间对仿真结果的影响以简化计算，从而解决了求解极小松弛时间（10^-13～10^-11 s）的多维GL方程的困难．展开更多
This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi...This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.展开更多
Without considering the influence of heat,existing fractal contact models are not applicable to analyze the contacts when the temperature changes.For this problem,the normal load model and the normal stiffness model o...Without considering the influence of heat,existing fractal contact models are not applicable to analyze the contacts when the temperature changes.For this problem,the normal load model and the normal stiffness model of thermal elasto-plastic contact of rough surfaces are developed respectively in this paper.The proposed model is based on the normal contact mechanics model of fractal theory of anisotropic and thermal elasto-plastic contact theory which can be used to characterize the rough surface thermodynamic properties.Then the validity of the model is verified.Finally,the influence of main parameters on the total normal load and the whole normal stiffness of thermal elasto-plastic contact at the interface is analyzed by contact simulation.The results show that the total normal load of thermal elasto-plastic contact increases with the increases of temperature.The whole normal stiffness of thermal elasto-plastic contact increases with increasing coefficient of linear expansion,scale factor,temperature difference or fractal dimension,but decreases with increasing fractal roughness.This model expands basic theory and applications of traditional models,and can be used to calculate and analyze the contacts when the temperature changes.展开更多
文摘为求解同时考虑时空耦合因素和松弛时间因素的高响应速度传热Green and Lindasy（GL）方程，设计了一个半无限长杆的一维GL导热问题，运用Laplace变换获得其解析解．通过比较无限长杆上短时间内的温度、应变、应力分布的解析解与数值仿真结果，得出不考虑松弛时间的温度分布的最大偏差不超过10K，应变和应力分布的最大偏差为5％。依据此结论，在应用GL模型研究高温燃气加热铝质活塞的低周热疲劳问题时，可以忽略松弛时间对仿真结果的影响以简化计算，从而解决了求解极小松弛时间（10^-13～10^-11 s）的多维GL方程的困难．
基金Projects(42477162,52108347,52178371,52168046,52178321,52308383)supported by the National Natural Science Foundation of ChinaProjects(2023C03143,2022C01099,2024C01219,2022C03151)supported by the Zhejiang Key Research and Development Plan,China+6 种基金Project(LQ22E080010)supported by the Exploring Youth Project of Zhejiang Natural Science Foundation,ChinaProject(LR21E080005)supported by the Outstanding Youth Project of Natural Science Foundation of Zhejiang Province,ChinaProject(2022M712964)supported by the Postdoctoral Science Foundation of ChinaProject(2023AFB008)supported by the Natural Science Foundation of Hubei Province for Youth,ChinaProject(202203)supported by Engineering Research Centre of Rock-Soil Drilling&Excavation and Protection,Ministry of Education,ChinaProject(202305-2)supported by the Science and Technology Project of Zhejiang Provincial Communication Department,ChinaProject(2021K256)supported by the Construction Research Founds of Department of Housing and Urban-Rural Development of Zhejiang Province,China。
文摘This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.
基金Project(52130501)supported by the National Natural Science Foundation of ChinaProject(LY20E050012)supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(Y201942581)supported by the Scientific Research Project of Education Department of Zhejiang Province,China。
文摘Without considering the influence of heat,existing fractal contact models are not applicable to analyze the contacts when the temperature changes.For this problem,the normal load model and the normal stiffness model of thermal elasto-plastic contact of rough surfaces are developed respectively in this paper.The proposed model is based on the normal contact mechanics model of fractal theory of anisotropic and thermal elasto-plastic contact theory which can be used to characterize the rough surface thermodynamic properties.Then the validity of the model is verified.Finally,the influence of main parameters on the total normal load and the whole normal stiffness of thermal elasto-plastic contact at the interface is analyzed by contact simulation.The results show that the total normal load of thermal elasto-plastic contact increases with the increases of temperature.The whole normal stiffness of thermal elasto-plastic contact increases with increasing coefficient of linear expansion,scale factor,temperature difference or fractal dimension,but decreases with increasing fractal roughness.This model expands basic theory and applications of traditional models,and can be used to calculate and analyze the contacts when the temperature changes.
