Electric conductivity and surface potential distributions in carbon fiber reinforced composites with different ply orientations

The electric conductivity and surface potential distributions of carbon fiber laminated panels with different ply orientations have been investigated. We found that the unidirectional (UD) lamina has higher conductivity along the carbon fiber direction than the perpendicular direction, and equipotential contours also show different gradients along the two directions. The cross-ply (CP) and quasi-isotropic (QI) laminates have the mixed effects of the UD lamina electric conductivity and ply orientations, while the surface potential distributions mostly depend on the surface lamina direction. The conductivity along the thickness direction depends on each lamina and inter-laminar bonding. A finite element analysis model was also developed to show the effect of ply orientation on potential distribution. The CP and QI laminates with 0° surface ply have uniform potential distributions and isotropic electricity behaviors. The results could be used to monitor damage locations and design electric composite materials.

Wear analysis of eco-friendly non-asbestos friction-lining material applied in an automotive drum brake: Experimental and finite-element analysis

Brake friction lining material is the critical element of a braking system, since it provides friction resistance to the rotating drum for controlling automobiles. The present study involves wear analysis of newly developed eco-friendly non-asbestos friction lining material for automotive drum brake applications using experimental study, finite-element analysis, and microstructural investigations. Theoretical interpretation of braking force at different automobile speeds was derived using fundamentals. Specimen drum brake liner with eco-friendly material compositions was produced using an industrial hot compression molding process at one of the manufacturer. The surface wear of the liner was measured using an effective and accurate method. Furthermore, a finite-element analysis model was developed considering actual operating conditions and various components of the drum brake system. The model was elaborated for various result outcomes, including Von-Mises stresses and total deformation of components of the drum brake, and further used to estimate the surface wear of the friction lining material in terms of transverse directional deformation. Finally, microstructural analysis of the friction lining material was carried out using scanning electron microscopy and energy dispersive spectroscopy. From the results, it is seen that the developed friction lining material is wear resistant. The finite-element analysis model can be effectively utilized to study the tribological characteristics of friction lining materials.

Multi-objective Optimization of Linear Proportional Solenoid Actuator

This paper employed a multi-objective Genetic Algorithm (GA) process to optimize the structure parameters of Linear Proportional Solenoid (LPS). And designed objectives include magnitude of static push force, stability of push force with displacement in working range and push force to mass ratio. A two-dimensional finite element analysis model is presented to reduce the large calculation time generated by GA process. The optimization process result of LPS shape parameters is obtained and the optimal LPS is manufactured. Through using a high-precision measuring device in the static push force test, a comparison result between conventional shape and optimal shape shows that the proposed optimization strategy is feasible.

The design of super long span pedestrian landscape cable stayed bridge with sightseeing bridge tower

According to the design requirements of the super long-span pedestrian landscape cable-stayed bridge in Lake view Park, a kind of sightseeing tower-style pedestrian landscape three-tower cable-stayed bridge structure system was proposed. Sightseeing tower type bridge tower structure and duck egg arched bridge tower replace traditional cable-stayed bridge tower structure. Through the establishment of Midas finite element analysis model, dynamic modal analysis research was carried out. The analysis shows that: the sightseeing tower structure and the cable-stayed bridge tower structure are combined into one, and the two have good structural matching.