Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications.
Degree: PhD, Automotive Engineering, 2019, Clemson University
Multi-material design is one of the most attractive methods for automakers to reduce production cost while achieving lightweighting to meet stringent regulations and fuel efficiency concerns. Lightweighting, parts consolidation, reduction in assembly time and cost, and diverse functionalities are some advantages to the use of multi-material design in the automotive industry. However, the current technology of multi-material manufacturing faces some drawbacks, such as high cycle time, the necessity of various tooling and machinery systems, tight tolerance requirements, and extended planning effort on the production line. In this study, a technique named the Hybrid Single Shot (HSS), which is similar to Polymer Injection Forming (PIF), is used to manufacture CF/Epoxy-Thermoplastic components in a single operation. Unlike the PIF method, a carbon fiber /epoxy prepreg sheet is used as an insert material instead of sheet metal. In this technique, an injected polymer melt behaves like a forming medium to form the inserted thermoset sheet, in a single operation. Molten polymer not only forms but also bonds with the thermoset sheet using the high temperature of the polymer, in one process. CF/Epoxy sheet with injected thermoplastic is a hybrid structure that combines high mechanical properties of thermoset composite with the toughness and complex geometries of injected thermoplastic into a single component. A feasibility study was conducted for developing an integrated technology for the manufacturing of thermoset CF/Epoxy prepreg sheet with an injection of polypropylene to overcome the high cycle time and production cost associated with the manufacturing of such hybrids. Several sample parts were manufactured to demonstrate the effect of the process parameters on the process performance and the appearance of the final hybrid component. Although the results were promising, it showed some practical challenges such as excessive penetration, inadequate deformation, and warpage. Various process and design parameters are applied to the hybrid single shot process to circumvent these challenges. For example, a lower injection speed rate and the injection temperature are applied to increase the viscosity to prevent the penetration of polymeric melt through the thermoset sheet. Also, to evaluate the impact of polymer injection on the degree of cure of the prepreg sheet, Differential Scanning Calorimetry (DSC) analysis is conducted at a different pre-heat time before and after injection. The results showed that an increase in pre-heating time and injection temperature significantly enhanced the curing of the prepreg sheet after injection. Further, the mechanical properties of the hybrid part will be examined to identify the effect of individual properties of CF/ Epoxy and PP on the final component. Another contribution of this study is that it avoids many difficulties that conventional TS/TP joining techniques face. Specifically, these traditional joining methods, namely mechanical fastening, adhesive…
Advisors/Committee Members: Srikanth Pilla, Committee Chair, Gang Li, David Schmueser, Huijuan Zhao.
Subjects/Keywords: Hybrid Single Shot; Prepreg Deformation; Thermoplastic Injection; Thermoset Forming
to Zotero / EndNote / Reference
APA (6th Edition):
Kazan, H. (2019). Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/2435
Chicago Manual of Style (16th Edition):
Kazan, Hakan. “Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications.” 2019. Doctoral Dissertation, Clemson University. Accessed September 21, 2019.
MLA Handbook (7th Edition):
Kazan, Hakan. “Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications.” 2019. Web. 21 Sep 2019.
Kazan H. Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications. [Internet] [Doctoral dissertation]. Clemson University; 2019. [cited 2019 Sep 21].
Available from: https://tigerprints.clemson.edu/all_dissertations/2435.
Council of Science Editors:
Kazan H. Hybrid Single Shot Manufacturing of Multi-Materials Structure for Automotive Applications. [Doctoral Dissertation]. Clemson University; 2019. Available from: https://tigerprints.clemson.edu/all_dissertations/2435