Notice of RetractionNumerical simulation and experiment on precision forging of driven spiral bevel gear
In this paper, the numerical simulation of precision forging on driven spiral bevel gear was explored based on its physical simulation. The forming stage and the metal flow characteristic were analyzed; thereby the process of precision forging was designed. The material was 20CrMnTi and the equipment was friction press. The workblank of driven spiral bevel gear was manufactured successfully at 950°C~1000°C. It was indicated that the numerical simulation of was reliable and effective. Moreover, the results would be beneficial to industrialization producing driven spiral bevel gears using precision forging.
Recent development of process simulation for industrial applications
Abstract Manufacturing technologies have advanced over the past decades in many areas. These include process control, manufacturing tolerances, die design, CAD/CAM and process simulation. The constant pressures on manufacturers to reduce cost, minimize lead times and improve quality are ongoing. Automotive, aerospace, energy products, fastener, metals producers and other manufacturing industries are very competitive. Margins are tight even during strong periods of the business cycle. In this paper, the application of process simulation, as applied to the forging, cold heading and heat treatment is discussed. Several applications are presented, with an emphasis on industrial cases.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.