The ffects of different laying angles on impact resistance and damage types of woven carbon fibre-reinforced polymer(CFRP)laminates were studied.The drop harmmer impact test and simulation analysis of woven CFRP lamin...The ffects of different laying angles on impact resistance and damage types of woven carbon fibre-reinforced polymer(CFRP)laminates were studied.The drop harmmer impact test and simulation analysis of woven CFRP laminates at four different velocities were carried out by means of the combination of experiment and explicit finite element analysis.The effect of impact velocity on damage pattern and fracture of woven CFRP laminates with eight layers and four laying angles(0°,15°,30°,and 45°)was studied by drop weight impact test,and the damage area of woven CFRP larminates with different laying angles was measured by ultrasonic nondestructive testing method.A user-defined material model was developed based on LS-DYNA to simulate the impact behavior of woven CFRP laminates.A finite element simulation model was established to effectively predict the complex damage evolution of woven CFRP laminates under low-speed impact loading.Its effectiveness was verified by impact response and damage crack pattern.The energy absorption and impact force of the laminated plate increase gradually from 0°to 45°in the laying angle of woven fabric.With the increase of laying angle from 0°to 459,the length of fracture crack and the damage area increase.The developed model can accurately predict the impact properties of the composites.展开更多
The primary energy demand increases, but a large amount of waste heat resources w</span><span style="font-family:Verdana;">ere </span><span style="font-family:Verdana;">...The primary energy demand increases, but a large amount of waste heat resources w</span><span style="font-family:Verdana;">ere </span><span style="font-family:Verdana;">not effectively used. To explore the influence of particle stacking structure on waste heat recovery process, CFD method was used to simulate. An unsteady heat transfer model of two particles was established, effect of particle stacking angle on heat transfer characteristics of the particles close to the wall under different initial temperature conditions was studied. Results show that: higher initial temperature, resulting in increased heat transfer time, the larger particle stacking angle causes the shortening of heat transfer time. When initial temperature is 1073</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">K, the average wall heat flux shows a trend of rapid decline first and then a slow one. At the same moment, the larger stacking angle causes smaller particle average temperature. The change of particle stacking angle shows a greater impact on the temperature of the particles close to adiabatic wall. The increase in the stacking angle resulting in better heat transfer characteristics between particles.展开更多
In this study,a simulation model of peanut pod particles during harvest in saline soil was tested to calibrate contact parameters.Discrete meta-fill models of peanut pods were generated by a 3D meter and EDEM software...In this study,a simulation model of peanut pod particles during harvest in saline soil was tested to calibrate contact parameters.Discrete meta-fill models of peanut pods were generated by a 3D meter and EDEM software.The range of values of contact parameters for peanut pods was measured by conducting collision and other tests using a homemade test rig.The parameters that affect the significance of the simulation process of stacking angle were screened by the Plackett-Burman experiment,the steepest ascent experiment,and the Box-Behnken experiment.An optimization test determined the optimal simulation model parameters:The peanut pods had a Poisson’s ratio of 0.386 and a shear modulus of 3.04 MPa.The coefficient of recovery for pods-pods collisions was 0.335,the coefficient of static friction was 0.854,and the coefficient of rolling friction was 0.346.The coefficient of recovery of collision between the pods-65Mn steel was 0.339,the coefficient of static friction was 0.589,and the coefficient of rolling friction was 0.159.The test results showed a relative error of 0.42%between the stacking angle bench and simulation tests.The results can provide data support for studying the discrete metamaterial characterization of peanut pods.展开更多
In the building environment,PM2.5 seriously affects people’s health and quality of life,so it is necessary to study the particle deposition characteristics.In addition,it is essential for a thorough investigation of ...In the building environment,PM2.5 seriously affects people’s health and quality of life,so it is necessary to study the particle deposition characteristics.In addition,it is essential for a thorough investigation of the dust removal mechanism to understand the non-spherical particles deposition characteristics.The stacking angle experiment was used to calibrate the discrete element simulation parameters.And four simulation methods(CFD-DPM,CFD-DEM,API interface loading drag model based on EDEM software and EDEM simulation)were used to numerically simulate the non-spherical particles deposition characteristics.The optimal simulation method EDEM was applied to study the non-spherical particles deposition characteristics in filter media,which saves the calculation time obviously.On this basis,the particle parameters on the particle deposition characteristics of filter media were investigated.The results show that the deposition rate of non-spherical(special shape)particles with the same volume is basically consistent on the filter media,hence it is more realistic that the dust actual shape is simplified into the triangular-shaped particles.As the particle size increases,the number of deposited particles on the filter media decreases.And the larger the particle size,the more dispersed the distribution.It has a significant impact on the number of particles deposited on the filter media when the particle velocity is 0.1 m/s.The particle deposits to the lower part of the filter media in the form of a parabola and deviates from the outlet seriously at 0.1 m/s.Moreover,it has little effect on the number of particle deposition at the other velocities,and most particles are deposited on the upper part of the filter media with the increase of particle velocity.展开更多
基金the Jilin Scientific and Technological Development Program(No.20170101130JC)the National Natural Science Foundation of China(Nos.51775227 and 51375201)。
文摘The ffects of different laying angles on impact resistance and damage types of woven carbon fibre-reinforced polymer(CFRP)laminates were studied.The drop harmmer impact test and simulation analysis of woven CFRP laminates at four different velocities were carried out by means of the combination of experiment and explicit finite element analysis.The effect of impact velocity on damage pattern and fracture of woven CFRP laminates with eight layers and four laying angles(0°,15°,30°,and 45°)was studied by drop weight impact test,and the damage area of woven CFRP larminates with different laying angles was measured by ultrasonic nondestructive testing method.A user-defined material model was developed based on LS-DYNA to simulate the impact behavior of woven CFRP laminates.A finite element simulation model was established to effectively predict the complex damage evolution of woven CFRP laminates under low-speed impact loading.Its effectiveness was verified by impact response and damage crack pattern.The energy absorption and impact force of the laminated plate increase gradually from 0°to 45°in the laying angle of woven fabric.With the increase of laying angle from 0°to 459,the length of fracture crack and the damage area increase.The developed model can accurately predict the impact properties of the composites.
文摘The primary energy demand increases, but a large amount of waste heat resources w</span><span style="font-family:Verdana;">ere </span><span style="font-family:Verdana;">not effectively used. To explore the influence of particle stacking structure on waste heat recovery process, CFD method was used to simulate. An unsteady heat transfer model of two particles was established, effect of particle stacking angle on heat transfer characteristics of the particles close to the wall under different initial temperature conditions was studied. Results show that: higher initial temperature, resulting in increased heat transfer time, the larger particle stacking angle causes the shortening of heat transfer time. When initial temperature is 1073</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">K, the average wall heat flux shows a trend of rapid decline first and then a slow one. At the same moment, the larger stacking angle causes smaller particle average temperature. The change of particle stacking angle shows a greater impact on the temperature of the particles close to adiabatic wall. The increase in the stacking angle resulting in better heat transfer characteristics between particles.
基金financially sponsored by the National Key Research and Development Program of China(Grant No.2022YFD2300100)Shandong Province Agricultural Major Technology Collaborative Extension Program Project(Grant No.SDNYXTTG-2024-15)the National Saline and Alkaline Land Comprehensive Utilization Technology Innovation Center Core Research Team Project(Grant No.NSALCUIC-2024).
文摘In this study,a simulation model of peanut pod particles during harvest in saline soil was tested to calibrate contact parameters.Discrete meta-fill models of peanut pods were generated by a 3D meter and EDEM software.The range of values of contact parameters for peanut pods was measured by conducting collision and other tests using a homemade test rig.The parameters that affect the significance of the simulation process of stacking angle were screened by the Plackett-Burman experiment,the steepest ascent experiment,and the Box-Behnken experiment.An optimization test determined the optimal simulation model parameters:The peanut pods had a Poisson’s ratio of 0.386 and a shear modulus of 3.04 MPa.The coefficient of recovery for pods-pods collisions was 0.335,the coefficient of static friction was 0.854,and the coefficient of rolling friction was 0.346.The coefficient of recovery of collision between the pods-65Mn steel was 0.339,the coefficient of static friction was 0.589,and the coefficient of rolling friction was 0.159.The test results showed a relative error of 0.42%between the stacking angle bench and simulation tests.The results can provide data support for studying the discrete metamaterial characterization of peanut pods.
基金financially supported by Anhui Provincial Scientific and Technological Major Project (No.18030801109).
文摘In the building environment,PM2.5 seriously affects people’s health and quality of life,so it is necessary to study the particle deposition characteristics.In addition,it is essential for a thorough investigation of the dust removal mechanism to understand the non-spherical particles deposition characteristics.The stacking angle experiment was used to calibrate the discrete element simulation parameters.And four simulation methods(CFD-DPM,CFD-DEM,API interface loading drag model based on EDEM software and EDEM simulation)were used to numerically simulate the non-spherical particles deposition characteristics.The optimal simulation method EDEM was applied to study the non-spherical particles deposition characteristics in filter media,which saves the calculation time obviously.On this basis,the particle parameters on the particle deposition characteristics of filter media were investigated.The results show that the deposition rate of non-spherical(special shape)particles with the same volume is basically consistent on the filter media,hence it is more realistic that the dust actual shape is simplified into the triangular-shaped particles.As the particle size increases,the number of deposited particles on the filter media decreases.And the larger the particle size,the more dispersed the distribution.It has a significant impact on the number of particles deposited on the filter media when the particle velocity is 0.1 m/s.The particle deposits to the lower part of the filter media in the form of a parabola and deviates from the outlet seriously at 0.1 m/s.Moreover,it has little effect on the number of particle deposition at the other velocities,and most particles are deposited on the upper part of the filter media with the increase of particle velocity.
