Process variable

About: Process variable is a research topic. Over the lifetime, 3983 publications have been published within this topic receiving 43130 citations. The topic is also known as: process parameter.

Continuous viscosity monitoring of glass

Abstract: A method for manufacturing glass comprises forming glass from molten mineral material, continuously discharging an auxiliary stream of molten mineral material, continuously measuring the temperature and the mass flow rate by laser means of the auxiliary stream, calculating the viscosity of the material using the measured mass flow rate and modifying a process parameter in response to the measured temperature and calculated viscosity of the auxiliary stream. The laser means is also disclosed.

Processing and mechanical properties evaluation of a commingled carbon-fibre/PA-12 composite ☆

Abstract: A carbon-fibre/PA-12, hybrid yarn, woven fabric material has been processed into laminates and mechanically tested to evaluate its suitability for high performance applications. The processing technique used was compression moulding. A process parameter investigation was carried out to determine the most suitable values of pressure, temperature and time at temperature required to economically produce laminates of high quality. Laminates were subsequently produced for a detailed material-testing programme. It was found that the hybrid yarn material exhibits excellent mechanical properties, particularly tension, open-hole tension, fracture and impact properties.

Laser Transmission Welding of Thermoplastics—Part I: Temperature and Pressure

Abstract: Modeling paper discusses the development of a model of laser transmission welding that can be used as an analytical design tool. Currently the majority of laser transmission welding (LTW) applications rely on trial and error to develop appropriate process parameters. A more rigorous design approach is not commonly used primarily due to the complexity of laser welding, where small material or process parameter changes can greatly affect the weld quality. The model developed in this paper also enables optimizing operating parameters while providing monetary and time saving benefits. The model is created from first principles of heat transfer and utilizes contact conduction that is a function of temperature and pressure, Gaussian laser distribution, and many material properties that vary with temperature including the absorption coefficient. The model is demonstrated through a design example of a joint between two polyvinyl chloride parts. The model is then validated with samples welded with a diode laser system using the operating parameters developed in a design example. Using the weld width as the primary output, the error between the model and the experimental results is 4.3%, demonstrating the accuracy of the model. DOI: 10.1115/1.2752527

Microstructure optimization in design of forging processes

Abstract: A new approach based on sensitivity analysis for optimizing the microstructure development during the forging processes is proposed in this work. The analytical sensitivities of the recrystallization volume fraction and dynamically recrystalized grain size with respect to the design variables are derived. The mean grain size in each finite element is introduced so that the complex recrystallization mechanics, such as no recrystallization, partial recrystallization and complete recrystallization are all considered. The objective is to minimize a function describing the variance of mean grain size and the average value of mean grain size in the whole final product. Two constraints are imposed on die underfill and excessive material waste. Two different kinds of design variables are considered, including state parameter (initial shape of billet) and process parameter (die velocity). The optimization scheme is demonstrated with the design of a turbine disk made of Waspaloy in non-isothermal forging process. The optimal initial shape of billet and the die velocity are obtained.