Simulation of the Vacuum Assisted Resin Transfer Molding Process
Abstract : A process model that includes the coupled phenomenon of resin flow and preform compaction was developed and used to simulate resin infiltration of a fibrous preform using the vacuum-assisted resin transfer molding (VARTM) process. Flow of resin through the distribution medium and preform were modeled as flow through porous media. The finite element/control volume method was used to calculate the infiltrating fluid pressure distribution and track the progression of the flow front. The simulation results were compared with data obtained during infiltration of a carbon fiber preform with an epoxy resin. The parameters measured include the flow front location, resin pressure, and preform thickness change. With accurate inputs, the flow front locations and resin pressure distribution can be accurately predicted. The predicted transverse displacements do not agree well with the experimental measurements. The reasons for the differences are discussed, and further investigations are recommended to develop a more accurate compaction model.
Prediction of Spring-back Deformation for CFRP Reflectors Manufactured using Various Processes
The Carbon Fiber Reinforcement Polymer (CFRP) is widely used in space application, automobile industries, aerospace and sports equipments because of good specific properties over conventional metals and alloys. Many composite manufacturing processes are accustomed nowadays depending on product size, shape and processing time. The hot air oven and Vacuum Assisted Resin Transfer Moulding (VARTM) are the low cost with high dimensional stability manufacturing method. In this research paper, CFRP reflectors have been manufactured using oven curing as well as VARTM process to predict spring-back deformation. The dimensions of the inner surface of the manufactured reflectors have been measured using 3D scanning techniques at different location. The deviation between theoretical CAD model and reflector dimensions at each location gives spring-back deformation for the manufactured CFRP reflectors. The laminate thickness and layup orientation have been considered as a processing parameters in reflector manufacturing. The comparison of spring-back deformation for manufactured reflectors with various process parameters using oven curing and VARTM manufacturing techniques have been carried out. The percentage difference in spring-back deformation is found within acceptable limit. The spring-back deformation decreases as laminate thickness increases.
Reconceptualizing Vagrancy and Reconstructing the Vagrant: A Socio-Legal Analysis of Criminal Law Reform in Canada, 1953-1972
This article explores significant reforms to the vagrancy section of the Criminal Code during the mid-to-late twentieth century. By locating the reforms within their unique social, political, and economic climates, I examine how they reconceptualized the offence of vagrancy and concomitantly reconstructed the vagrant as a social problem. The reforms played a seminal role in reducing the number of vagrancy offences, eventually leading to the demise of vagrancy in the criminal law. Yet, while the "vagrant" ceased to exist in the law, the law still continues to preserve vestiges of the vagrant in a highly gendered manner.