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.
Manufacturing Technologies of Carbon/Glass Fiber-Reinforced Polymer Composites and Their Properties: A Review
Over the last few years, there has been a growing interest in the study of lightweight composite materials. Due to their tailorable properties and unique characteristics (high strength, flexibility and stiffness), glass (GFs) and carbon (CFs) fibers are widely used in the production of advanced polymer matrix composites. Glass Fiber-Reinforced Polymer (GFRP) and Carbon Fiber-Reinforced Polymer (CFRP) composites have been developed by different fabrication methods and are extensively used for diverse engineering applications. A considerable amount of research papers have been published on GFRP and CFRP composites, but most of them focused on particular aspects. Therefore, in this review paper, a detailed classification of the existing types of GFs and CFs, highlighting their basic properties, is presented. Further, the oldest to the newest manufacturing techniques of GFRP and CFRP composites have been collected and described in detail. Furthermore, advantages, limitations and future trends of manufacturing methodologies are emphasized. The main properties (mechanical, vibrational, environmental, tribological and thermal) of GFRP and CFRP composites were summarized and documented with results from the literature. Finally, applications and future research directions of FRP composites are addressed. The database presented herein enables a comprehensive understanding of the GFRP and CFRP composites’ behavior and it can serve as a basis for developing models for predicting their behavior.
The Illinois Legislature
It further provides that the county must have voted "for license" at the last general election on that subject. Also, that the petition, together with all names and addresses on it, must first be published in at least two issues of some newspaper published in the town where the petition was circulated, for at least ten days before the petition is acted upon. Any officer authorized to issue licenses violating the provisions of this act is liable to a fine of from $500 to $1000 and imprisonment in the county jail for from two to twelve months. The act does not repeal any local laws forbidding the sale of liquor, but is cumulative to all anti-liquor laws now in force. The final section is: "This Act being necessary for the public peace, health, and safety, shall take effect and be in force from and after December 31, 1913." The postponement of the time for going into effect was made io order not to interfere with licenses already issued and to give the liquor dealers time to adjust themselves to the provisions of the act. But the liquor people denied that the emergency clause could be attached to an act the operation of which was postponed nearly a year. They called attention to the omission of the word "immediate," and declared that the postponement was in itself sufficient evidence that it was not necessary for the "immmediate preservation of the public health, peace and safety." A petition for reference was circulated and the necessary number of signatures was secured. The attorney-general was first asked for his opinion as to whether the act was subject to the referendum. That officer stated that he could find no precedent for such a case. Basing his decision on reason and common sense he declared the act not subject to the referendum. The circuit court was then asked for a write of mandamus against the secretary of state to compel him to submit the act, but the court refused to grant it, saying that the attachment of the emergency clause was evidence that the legislature intended to prevent its submission. At this writing the question is pending on appeal before the supreme court.