Machining process model based on virtual reality environment

Abstract

Virtual manufacturing is fast becoming an affordable technology with wide-ranging applications in modern manufacturing. Its advantages over existing technology are primarily that users can visualize, feel involvement and interact with virtual representations of real world activities in real time. In this paper, a virtual cutting system is built which can simulate turning process, estimate tool wear and cutting force using artificial neural network etc. Using the simulated machining environment in virtual reality (VR), the user can practise and preview the operations for possible problems that might occur during implementation. This approach enables designers to evaluate and design feasible machining processes in a consistent manner as early as possible during the development process.

Polymerization and Rheological Behavior of the Thermoresponsive Gelcasting System Based on N‐isopropylacrylamide

“…For the gelcasting process, the induction period should be optimized by changing the aforementioned conditions and needs to be in the range 300–1800 s. Free radical polymerization is very sensitive to the amount of catalyst and is difficult to control by changing the catalyst . According to previous studies, 4 mL/L of catalyst is suitable for the IPAM gelcasting system. Under this condition (4 mL/L of catalyst), the induction periods of solutions with 0.25 to 0.7 mg/mL meet the requirement of the process at 15°C or 20°C, as shown in Fig.…”

“…However, in practice, the induction period of suspensions is affected by the suspended powder, solvent, viscosity of the suspension, and even the flow during mixing and casting. For example, high viscosity accelerates gelation . Because of this effect, 0.25–0.5 mg/mL of initiator is considered optimal for temperatures between 15°C and 20°C, which will be confirmed by the consolidation of suspensions (see Fig.…”

“…Furthermore, when the amount of initiator was 0.25 mg/mL, the induction period was longer than 2500 s and gelation seemed not to occur. It is contributed to that the free radicals generated from the initiator at low temperature (15°C) are not enough to trigger the polymerization reaction . However, at 20°C, the induction periods with the same amount of initiator and catalyst decreased, as shown in Fig.…”

“…The calculated values of E a for initiator additions of 0.5 and 0.75 mg/mL are 99.99 and 75.48 kJ/mol, respectively. These results are similar to the E a of the acrylamide gelcasting system (71.2 kJ/mol) . This indicates that the IPAM gelcasting system is still controllable in the low temperature range (10–25°C).…”

“…The induction period of the aqueous system is about 820 s while that of the suspension with 55 vol.% solids loading is 340 s. This can be attributed to the fact that the viscosity of the suspension increases with increasing solids loading. High viscosity hinders the diffusion of free radicals and thus accelerates the polymerization reaction . In addition, during the induction period, the G ′ values also increase with increasing solids loading.…”