Most of the research carried out on hypervelocity collisions, of the kind encountered in space, assume that the projectile hits a stationary target. In reality, both the target and the projectile are moving at high velocity in a non-colinear fasion. We present here a study of this phenomenon and its rfelationship with oblique impact.
A number of authors have experimentally assessed the influence of friction on adhesive contacts, and generally the contact area has been found to decrease due to tangential shear stresses at the interface. The decrease is however generally much smaller than that predicted already by the Savkoor and Briggs 1977 classical theory using “brittle” fracture mechanics mixed mode model extending the JKR (Griffith like) solution to the contact problem.
EML Webinar on July 29, 2020 will be given by Professor Teng Li, the University of Maryland via Zoom meeting. Discussion leader: Professor Zheng Jia, Zhejiang University.
Title: Advanced Materials toward a Sustainable Future: Mechanics Design
Time: 7 am California, 10 am Boston, 3 pm London, 10 pm Beijing on July 29, 2020
The interaction between contact area and frictional forces in adhesive soft contacts is receiving much attention in the scientific community due to its implications in many areas of engineering such as surface haptics and bioin-spired adhesives. In this work, we consider a soft adhesive sphere that is pressed against a rigid substrate and is sheared by a tangential force where the loads are transferred to the sphere through a normal and a tangential spring, representing the loading apparatus stiffness.
The conflict between the acoustical performance and ventilation efficiency in conventional noise barriers limits their application potentials in several settings. To address this challenge, we design and experimentally demonstrate a ventilated tunable acoustic metamaterial for noise mitigation at targeted frequencies. Through the structure, a peak normal incidence sound absorption coefficient of more than 0.96 at 1000 Hz and the peak normal incidence sound transmission loss of 18 dB is achieved while maintaining the air circulation with a 45% open area of ventilation.
Digital Light Synthesis (DLS) technology creates ample opportunities for making 3D printed soft polymers for a wide range of grades and properties. In DLS, a 3D printer uses a continuous building technique in which the curing process is activated by an ultra-violet (UV) light. In this contribution, EUP40, a recently invented commercially available elastomeric polyurethane (EPU) printed by the DLS technology, is experimentally characterized.
I would like to share an article that was recently published in CMAME.
It is about MicroStructPy, a very flexible microstructure generator able to represent various statistics for microstructures with multiple phases. It works in 2D and 3D and you can provide, for each phase, grain size distributions, volume fraction, elongation and orientation distribution for elongated grains, etc.
