Additive manufacturing of fibrous sound absorbers

An Optimization Model for Fibrous Metal Foam Sound Absorbers

It is well-established that wool and glass fibers are good absorbers for noise-control in air. However, inadequate levels of stiffness and strength have limited the range of the use of such fibers. The emergence of fibrous metal foams has meant rethinking of these limitations. Fibrous metal foams can be filled, not just with air, but also with other types of fluids. This means that altering bot...

Application of Additive Manufacturing in Marine Industry

The advantage of additive manufacturing (AM) (e.g. reasonable time and expense in prototyping, and reliable product) has triggered the idea of using this method in manufacturing of marine vessels components. The current article tries to introduce basic concepts of AM method and its application in marine industry; have a glance at additive-manufactured parts microstructure; elaborate the challen...

Vibroacoustics of thin micro-perforated sound absorbers

Effect of porosity on the characteristics of underwater acoustic sound absorbers using theoretical models‎

Porous materials have good acoustic damping characteristics over a wide frequency range. As for sound waves, many small-scale pores in the coating materials can convert underwater-coating to rough surfaces. The main property of porous absorbents is their resistance against incident sound wave that leads to damping effect. From a physical point of view, damping occurs due to friction between flu...

Living Additive Manufacturing

Living organisms such as bacteria are able to grow, respond to stimuli, and divide as part of their life cycle. Designing smart three-dimensional (3D) materials that are able to perform such feats, i.e., continue on-demand growth and respond to external stimuli, is always a challenge for polymer and material scientists. At present, Johnson and co-workers have made a significant step forward in ...