Improvement of structural efficiency in various materials is critically important for sustainable society development and the efficient use of natural resources. Recently, a lot of attention in science and engineering has been attracted to heterogeneous-structure materials because of high structural efficiency. However, strategies for the efficient design of heterogenous structures are still in their infancy therefore demanding extensive exploration. In this work, two-dimensional finite-element models for pure nickel with bimodal distributions of grain sizes having ‘harmonic’ and ‘random’

The effect of components' thermal properties in addition to their geometric configuration on the developed thermal stress in a model printed circuit board (PCB) is investigated. This effect is quantified through three parameters, the average normalized temperature gradient, maximum normalized temperature gradient and the uniformity factor. It is found that the effect of the geometric configuration, especially that of the heat-generating component, is more significant than the thermal properties of the components. © 2019 IEEE.

Organic solar cells have many advantages such as their ease of manufacturing, flexibility, and low cost compared to perovskite and silicon solar cells. However, increasing their power conversion efficiency (PCE) is still challenging. In this paper, response surface methodology of design of experiments (DOE) is used to optimize the PCE of a tandem organic solar cell. The cell is based on boron sub-phthalocyanine to reduce the series resistance between the layers. The optimization process is performed by formulating an empirical polynomial regression model relating the PCE to the active layers'

This research studies the vibration analysis of Euler-Bernoulli and Timoshenko beams utilizing the differential quadrature method (DQM) which has wide applications in the field of basic vibration of different components, for example, pillars, plates, round and hollow shells, and tanks. The free vibration of uniform and nonuniform beams laying on elastic Pasternak foundation will be studied under three sets of boundary conditions, that is, mixing between being simply upheld and fixed while utilizing the DQM. The natural frequencies and deflection values were produced through the examination of

Submerged breakwaters are efficient structures used for shore protection. Many design features of these structures are captured upon modeling wave propagation over submerged square obstacles. The presence of separation vortices and large free surface deformations complicates the problem. A multiphase turbulent numerical model is developed using ANSYS commercial package. Careful domain discretization is done employing suitable mesh clustering to capture high gradients. Various numerical model parameters are provided, including grid size and time step. Special attention is directed towards

This study aims to investigate the Hitec molten salt's thermal-hydraulic behavior in a smooth round pipe under broad ranges of surface heat flux and Reynolds number (q = 104 - 105 W/m2, Re = 104 - 105). Mesh independent study was performed to ensure the robustness of the model to achieve accurate solutions. Presentation of temperature, pressure and thermophysical properties for multiple cases are presented and discussed. Temperature gradient decreases at high Reynolds number leading to small change in thermo-physical properties. While pressure seems not to be affected by the change in the

This paper experimentally investigates the effect of the manufacturing method and metal reinforcement option on the natural frequency and damping behavior of five polymer and Fiber Reinforced Polymer (FRP) composite pipes. The five pipes are made of polymer, roll-wrapped woven glass FRP, metal-reinforced roll-wrapped woven glass FRP, filament-wound glass FRP, and metal reinforced filament-wound-up glass FRP. The composite pipes can replace conventional pipes in oil and gas industries and conventional metallic shafts in many applications. Logarithmic decay, logarithmic decrement, and random

The nonlinear interaction between an elastic Euler beam and a tensionless soil foundation is studied. Exact analytical solutions of the challenging problem are rather complicated. The basic obstacle is imposing compatibility conditions at lift-off points. These points are determined as a part of the solution although being needed to get the solution itself. In the current work, solutions are derived using the approximate Rayleigh-Ritz method. The principal of vanishing variation of potential energy is adopted. The solution is approximated using a set of suitable trial functions. Lift-off

Background: The buckling load as well as the natural frequency under axial load for non-prismatic beam is a changeling problem. Determination of buckling load, natural frequency, and elastic deflection is very important in civil applications. The current paper used both perturbation method (PM), analytic method, and differential quadrature method (DQM), numerical method, to find buckling load and natural frequency with different end supports. The deflection of the beam resting on an elastic foundation under transverse distributed and axial loads is also obtained. Both PM and DQM are used for

In this paper, we introduce active material for an organic solar cell with a modified composition. A combination of P3HT: PCBM with parallel vertical LiF cylinders formulate the active material structure. The collection efficiency in the active material reaches 92.2%. The operating wavelength where the maximum collection efficiency occurs is adjusted and matched with the wavelength where the maximum irradiance of the solar spectrum occurs. The absorption per unit volume of the new structure is 80.4 μm-3 while the blank structure is 75.07 μm-3. The net absorption magnitude for the required