Bio-inspired helicoidal composite laminates,inspired by the intricate helical structures found in nature,present a promising frontier for enhancing the mechanical properties of structural designs.Hence,this study prov...Bio-inspired helicoidal composite laminates,inspired by the intricate helical structures found in nature,present a promising frontier for enhancing the mechanical properties of structural designs.Hence,this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates.The inverse hyperbolic shear deformation theory(IHSDT)of plates is employed to characterize the displacement field,with the incorporation of Green-Lagrange nonlinearity.The problem is modeled using the C0finite element method(FEM),and an in-house code is developed in the MATLAB environment to solve it numerically.Various helicoidal layup configurations including helicoidal recursive(HR),helicoidal exponential(HE),helicoidal semi-circular(HS),linear helicoidal(LH),and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied.The model is validated,and parametric studies are conducted.These studies investigate the effects of layup configurations,side-to-thickness ratio,modulus ratios,boundary conditions,and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates.The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors.Moreover,this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.展开更多
For planetary surface materials,thermal inertia is the critical property that governs the surface’s daily thermal response and controls diurnal and seasonal surface temperature variations.Here we use the ground measu...For planetary surface materials,thermal inertia is the critical property that governs the surface’s daily thermal response and controls diurnal and seasonal surface temperature variations.Here we use the ground measurements made by the MSL Curiosity rover and the InSight lander to determine the thermal inertia of two sites on Mars.This study compares the variation of thermal inertia during and after the Large Dust Storm(LDS)of Martian Year(MY)34.To determine surface thermal inertia,we derive a simple approximation(using energy balance),which utilizes surface albedo,surface energy flux,and diurnal change in the surface temperature.The average thermal inertia in MY34 is about 39.2%,3.7%,and 3.4%higher than MY35 average thermal inertia for the MSL,InSight(FOV1),and InSight(FOV2),respectively.Notably,the thermal inertia at the InSight(FOV1)is consistently lower by about 20 J·m^(-2)·s^(-1/2)·K^(-1) than the InSight(FOV2)site for all scenarios,indicating variation in the region’s surface composition.The best-fit surface albedo in MY34(determined using the KRC model)are about 0.08,0.05,and 0.03 higher than MY35 surface albedo for the MSL,InSight(FOV1),and InSight(FOV2),respectively.An increase in both surface albedo and thermal inertia during the LDS indicates that the underlying surface is both more thermally resistant and more reflective than the overlying loose dust.展开更多
文摘Bio-inspired helicoidal composite laminates,inspired by the intricate helical structures found in nature,present a promising frontier for enhancing the mechanical properties of structural designs.Hence,this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates.The inverse hyperbolic shear deformation theory(IHSDT)of plates is employed to characterize the displacement field,with the incorporation of Green-Lagrange nonlinearity.The problem is modeled using the C0finite element method(FEM),and an in-house code is developed in the MATLAB environment to solve it numerically.Various helicoidal layup configurations including helicoidal recursive(HR),helicoidal exponential(HE),helicoidal semi-circular(HS),linear helicoidal(LH),and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied.The model is validated,and parametric studies are conducted.These studies investigate the effects of layup configurations,side-to-thickness ratio,modulus ratios,boundary conditions,and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates.The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors.Moreover,this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.
文摘For planetary surface materials,thermal inertia is the critical property that governs the surface’s daily thermal response and controls diurnal and seasonal surface temperature variations.Here we use the ground measurements made by the MSL Curiosity rover and the InSight lander to determine the thermal inertia of two sites on Mars.This study compares the variation of thermal inertia during and after the Large Dust Storm(LDS)of Martian Year(MY)34.To determine surface thermal inertia,we derive a simple approximation(using energy balance),which utilizes surface albedo,surface energy flux,and diurnal change in the surface temperature.The average thermal inertia in MY34 is about 39.2%,3.7%,and 3.4%higher than MY35 average thermal inertia for the MSL,InSight(FOV1),and InSight(FOV2),respectively.Notably,the thermal inertia at the InSight(FOV1)is consistently lower by about 20 J·m^(-2)·s^(-1/2)·K^(-1) than the InSight(FOV2)site for all scenarios,indicating variation in the region’s surface composition.The best-fit surface albedo in MY34(determined using the KRC model)are about 0.08,0.05,and 0.03 higher than MY35 surface albedo for the MSL,InSight(FOV1),and InSight(FOV2),respectively.An increase in both surface albedo and thermal inertia during the LDS indicates that the underlying surface is both more thermally resistant and more reflective than the overlying loose dust.
