inhibitory effect of double-base solid propellants is exerted to control and prevent the burning degree of the exposed area which is due to longer burning time. in this research a composite inhibitor based on cotton fibers/epoxy resin was manufactured by filament winding technique. some flame retardant materials such as antimony trioxide and tetrachlorophthalic anhydride were employed as the co...

A new stellarator coil design code is introduced that optimizes the position and winding pack orientation of finite-build coils. The code, called FOCUSADD, performs gradient-based optimization in a high-dimensional, non-convex space. derivatives with respect to parameters coils are easily efficiently computed using automatic differentiation. FOCUSADD parametrizes positions free space Fourier se...

Measuring the geometric imperfections in cylindrical shells is a critical step necessary to create accurate numerical models that can capture imperfection-sensitive behavior of these structures. Modern composite structures, such as variable–angle filament–wound (VAFW) cylinders, have unique imperfection signature still unknown scientific community. This new class variable–stiffness structures d...

This work reports the high-velocity impact response of multiscale anisogrid composite (AGC) panels. The aim of the present study is to evaluate the influence of surface-modified multi-walled carbon nanotubes (S-MWCNTs) at different S-MWCNTs contents (0-0.5 wt.% at an interval of 0.1 wt.%) on the high-velocity impact responses of E-glass/epoxy AGC. Surface modification of MWCNTs is confirmed by ...

The high costs related to the production of composite products force firms to a better utilization of the plants. Different actions can be taken in order to decrease the use of human resources and to automate the entire process. The paper proposes a new policy for the generation of the part program in robotic filament winding process in order to deal with non-simple shape products. The proposed...

This paper presents a simplified computation approach for the machine path (or winding trajectory) of grid structures and tubes with circular cross-section angle-ply or double-double layup. The solution is given through controllable degrees freedom low-cost two-axis filament (FWM): mandrel rotation translation delivery eye along axis mandrel. efficiency analytical FWM was ascertained by automat...

This work aims to enhance and validate a systematic approach for the structural finite element (FE) analysis of thermoplastic impregnated 3D filament winding structures (fiber skeletons). The idealized modeling geometrically complex fiber skeletons used in previous publications is refined by considering additional characteristic dimensions investigating their mechanical influence. Moreover, tra...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...