To control underwater acoustic radiation of ships and protect against detection, coatings are attached to the vibrating wet surface of the hulls. Coatings with different pores or scatterers enclosed will attenuate vibration and suppress sound radiation with different mechanisms. However, there are very few experimental studies concerning vibration measurement of a coated structure in water, mai...

The design process is becoming increasingly complex with designers balancing societal, environmental and political issues. Composite materials are attractive to designers due to excellent strength to weight ratio, low corrosion and ability to be tailored to the application. One problem with composite materials can be the low stiffness that they exhibit and as such for many applications they are...

A fast vibration reduction optimization approach accelerated by the global proper orthogonal decomposition (POD) reduced-order model (ROM) is proposed, aiming at increasing efficiency of frequency response analysis and complex thin-walled shells. At offline stage, POD ROM adaptively updated using sample configurations generated CV (cross validation)–Voronoi sequence sampling method. In comparis...

This paper proposes an explicit method for topology optimization of stiffened plate structures. The present work is devoted to simultaneously optimizing stiffeners’ shape, size and layout by seeking the optimal geometry parameters a series moving morphable components (MMC). stiffeners with straight skeletons curved are considered enhance modeling capability current approach. All represented und...

Abstract In a pressure vessel, spherical crown head can be used as an end or middle head. Without common tangent to connect the surfaces of shell and cylindrical shell, connection between produces stresses deformation at edge connection, so in use need stiffened stiffening section needs arranged. With section, stainless steel equipment includes more welding beads looks less aesthetically attrac...

Insect wings do not contain intrinsic musculature to change shape, but rather bend and twist passively during flight. Some insect wings feature flexible joints along their veins that contain patches of resilin, a rubber-like protein. Bumblebee wings exhibit a central resilin joint (1m-cu) that has previously been shown to improve vertical force production during hovering flight. In this study, ...

Fiber metal laminates (FMLs) have been successfully manufactured by the vacuum assisted resin transfer molding (VARTM) process developed at NASA Langley Research Center. A flow visualization fixture of the FML, VARTM process was constructed and used to observe the resin infiltration process. Results of the flow visualization experiments are reported and compared with the predictions of a VARTM ...