The product development process usually encompasses a very complex and interdisciplinary environment in which product is seen by different views related with the life-cycle functions. An approach based on information models can provide an integrated view of the product, supporting also product information and knowledge (I&K) reuse acquired in previous development processes. This paper discusses...

The static friction coefficient between two materials is considered to be a material constant. We present experiments demonstrating that the ratio of shear to normal force needed to move contacting bodies can, instead, vary systematically with controllable changes in the external loading configuration. Large variations in both the friction coefficient and consequent stress drop are tightly link...

Metal forming processes, compared with machining ones, reduce production steps and increase manufacturing speed in addition to saving raw material. In this paper, forming process of column of a steering mechanism is investigated by finite element analyses and experimental tests; and optimum die design parameters are found. Forming process parameters including die opening angle, bearing length, ...

12.7-mm thick plates of 6061-T6511 aluminum alloy and high hardness steel (528 HV) were successfully joined by a friction stir bonding process using a tungsten Process parameter variation experiments, which geometry, plunge and traverse rates, tool offset, spindle tilt, and rotation speed, were conducted to develop a parameter set which yielded a defect free joint. Laboratory tensile tests exhi...

To improve product quality in high-tech industrial fields and in precision product processes, high precision position control systems have been developed. However, high precision position control systems have been faced with a friction problem that exists between the contact surfaces of two materials and produces an obstacle to the precise motion, because the friction is very sensitive to nonli...

A kind of 2.5-dimensional C/C-SiC composites was fabricated by using Isothermal Chemical Vapour Infiltration process (ICVI). Frictional properties of this material were evaluated by using MM-1000 under dry condition. Average dynamic friction coefficient of it was 0.16, static friction coefficient and average coefficient stability were 0.15 and 0.56, respectively. However, weight wear rate was l...

We have constructed a sliding block cryotribometer designed to measure friction at cryogenic temperatures and UHV conditions. An optical cryostat and high speed video was used to monitor the motion of the block. The temperature range of the measurements was 4–460 K. Both the static and dynamic friction coefficients were determined for a steel ball on stainless steel, sapphire, and PTFE (Teflon)...

The fibre concentrations generated during the production of friction materials, incorporating asbestos, over the past 60 years have been studied to provide cumulative dust exposure data for a mortality study of the work-force. Chrysotile has been used almost exclusively during this period. The measurements made routinely by the factory staff provided information from 1950 onwards; concentration...

The main challenge in predicting sliding friction is related to the complexity of highly nonequilibrium processes, the kinetics of which are controlled by the interface temperature. Our experiments reveal a nonmonotonic enhancement of dry nanoscale friction at cryogenic temperatures for different material classes. Concerted simulations show that it emerges from two competing processes acting at...

In the discrete element simulation of granular materials, the modelling of contacts is crucial for the prediction of the macroscopic material behaviour. From the tribological point of view, friction at contacts needs to be modelled carefully, as it depends on several factors, e.g. contact normal load or temperature to name only two. In discrete element method (DEM) simulations the usage of Coul...