Vibration and buckling analyses of nanobeams embedded in an elastic medium

Boundary characteristic orthogonal polynomials are used as shape functions in the Rayleigh–Ritz method to investigate vibration and buckling of nanobeams embedded in an elastic medium. The present formulation is based on the nonlocal Euler–Bernoulli beam theory. The eigen value equation is developed for the buckling and vibration analyses. The orthogonal property of these polynomials makes the computation easier with less computational effort. It is observed that the frequency and critical buckling load parameters are dependent on the temperature, elastic medium, small scale coefficient,and length-to-diameter ratio. These observations are useful in the mechanical design of devices that use carbon nanotubes.

Kinetic theory for aquatic animal distribution simulation

Identifying the underlying mechanisms that influence the spatial patterns in populations improves the forecasts of the alternative management strategies on the spatial dynamics of the populations, which are critical for assessing and managing the fisheries and improving the water resource management. This paper described a new approach of the numerical model for the prediction of the aquatic animal distribution in the flows. The model was developed based on the kinetic theory of gases, the mechanism of the aquatic animal movement and the flow hydrodynamic patterns. The model was validated using the available experimental data and an acceptable agreement was obtained. A comprehensive parameter study was then conducted to help understand the impact and the sensitivity of each parameter to the aquatic animal distribution. The promising results of the model reveal the prospect of applying this model to the reliable prediction of the aquatic animal distribution within a relatively large water area.

Study on Functional Mechanical Performance of Honeycomb Array Structures Inspired by Gideon Beetle

To obtain bio-inspired structures with superior biological function,four bio-inspired structures named regular arrangement honeycomb structure(RAHS),staggered arrangement honeycomb structure(SAHS),floral arrangement honeycomb structure(FLAHS)and functional arrangement honeycomb structure(FUAHS)are designed by observing the microstructure of the Gideon beetle,based on the optimal size bio-inspired cells by response surface method(RSM)and particle swarm optimization(PSO)algorithm.According to Euler theory and buckling failure theory,compression deformation properties of bio-inspired structures are explained.Experiments and simulations further verify the accuracy of theoretical analysis results.The results show that energy absorption of FLAHS is,respectively,increased by 26.95%,22.85%,and 121.45%,compared with RAHS,SAHS,and FUAHS.Elastic modulus of FLAHS is 110.37%,110.37%,and 230.56% of RAHS,SAHS,and FUAHS,respectively.FLAHS perfectly inherits crashworthiness and energy absorption properties of the Gideon beetle,and FLAHS has the most stable force.Similarly,RAHS,SAHS,and FUAHS,respectively,inherit mechanical properties of the Gideon beetle top horn,the Gideon beetle middle horn,and the abdomen of the beetle.This method,designing bio-inspired structures with biological functions,can be introduced into the engineering field requiring the special function.