The Development of a Surface Waviness Pattern During Brake-Like Applications

Author(s):  
Janko Slavicˇ ◽  
Miha Boltezˇar

Dynamical systems with contacts are often exposed to wear even under small loads. The wear develops at the micro, macro or global level and changes the contact shape. This changed contact shape alters the dynamics of the system and can further increase the wear. This research presents a numerical investigation of the interaction between the wear at the contacts and the dynamics. The research involves a dynamical model normally used in the research of car-brake dynamics and simulates the run-in wear of the brake pad and the development of waviness on disc. Special attention is given to the real roughness of the contacting surfaces and to on exact numerical simulation; because concurrent contacts between rough asperities occur, a specifically developed multibody dynamics approach is presented. This research shows that after the run-in period a concave pad produces a waviness pattern on the disc. Using a spectral analysis of the disc’s surface it is possible to show the effect of the wear particle-size and the pad-width on the surface waviness.

2014 ◽  
Vol 71 (2) ◽  
Author(s):  
Hussain, S. ◽  
M.K Abdul Hamid ◽  
A.R Mat Lazim ◽  
A.R. Abu Bakar

Brake wear particles resulting from friction between the brake pad and disc are common in brake system. In this work brake wear particles were analyzed based on the size and shape to investigate the effects of speed and load applied to the generation of brake wear particles. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) was used to identify the size, shape and element compositions of these particles. Two types of brake pads were studied which are non-asbestos organic and semi metallic brake pads. Results showed that the size and shape of the particles generatedvary significantly depending on the applied brake load, and less significantly on brake disc speed. The wear particle becomes bigger with increasing applied brake pressure. The wear particle size varies from 300 nm to 600 µm, and contained elements such as carbon, oxygen, magnesium, aluminum, sulfur and iron.


Author(s):  
Chang Ye ◽  
Gary J. Cheng

In this paper, numerical simulation of nanoparticle integrated laser shock peening of aluminum alloys was carried out. A “tied constraint” was used to connect the matrix and nanoparticle assembly in ABAQUS package. Different particle size and particle volumes fraction (PVF) were studied. It was found that there is significant stress concentration around the nanoparticles. The existence of nanoparticle will influence the stress wave propagation and thus the final stress and strain state of the material after LSP. In addition, particle size, PVF and particle orientation all influence the strain rate, static residual stress, static plastic strain and energy absorption during the LSP process.


2020 ◽  
Vol 45 (11) ◽  
pp. 9171-9185
Author(s):  
Cun Zhang ◽  
Zhaopeng Ren ◽  
Dingyi Hao ◽  
Tong Zhang

Author(s):  
Shriram B. Pillapakkam ◽  
Pushpendra Singh

In a recent study we have shown that when small particles, e.g., flour, pollen, glass, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. The vertical motion of a particle during its adsorption causes a radially-outward lateral (secondary) flow on the interface that causes nearby particles to move away. We present direct numerical simulation results for the adsorption of particles and show that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface. Although the importance of inertia diminishes with decreasing particle size, on an air-water interface the inertia continues to be important even when the size is as small as a few nanometers.


Sign in / Sign up

Export Citation Format

Share Document