Engineering Commons^™

Synthesis And Characterization Of Non-Pgm Catalysts For Fuel Cell Applications, Sudharsan Sridhar

Masters Theses

Fuel Cells convert the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. Proton Exchange Membrane (PEM) fuel cells convert (efficiency-60%) hydrogen and air to power the electric motors with zero emissions, facilitating the development of environmentally friendly and sustainable automobile technologies. One of the major obstacles for larger commercial viability of Fuel Cells for automobile applications is their cost-effectiveness. Currently, fuel cells use platinum as a catalyst material, which is prohibitively expensive for commercial automobile applications. The development of non-Platinum Group Metal (non-PGM) catalyst materials with similar electrochemical performance to that …

Material Properties And Heat Transfer Parameters In Compression Molding Of Glass Mat Thermoplastics, Cheng Xu

Electronic Thesis and Dissertation Repository

The compression molding of glass mat thermoplastics (GMT) allows high volume manufacture of composite parts with a short production cycle. Computer simulation is often used to assist process development and optimization. Reliable simulation depends on input of material property parameters and accurate prediction of heat transfer. This thesis developed experimental methods to characterize material property and heat transfer process parameters. Results were obtained by applying the methods to a selected commercial GMT sheet. Heat transfer coefficients including convection coefficients during pre-heating and transfer, as well as contact conductance at sheet-mold interface were estimated by a parameter-fitting approach. Viscoelastic parameters of …

Investigation Of The Impact Of Material Models On Reliability Assessment Of Electronic Packages, Abel Misrak

Mechanical and Aerospace Engineering Dissertations

Drop testing, thermal cycling, power cycling, etc. are some of the tests used to assess the reliability of new electronic products. However, performing experimental study of every new design is costly and time consuming. Computational tools are often employed to perform the required reliability analysis in a shorter time period and save valuable resources. Extensive set of material characterization work needs to be done before an accurate material model can be developed and used in computational analysis. Structural components such as printed circuit boards (PCBs) are critical in the thermomechanical reliability assessment of electronic packages. The bulk material properties of …

Prediction Of Isotropic Strain Hardening Material Properties Using Gradient Boosted Regression Tree Method And Hyperparameter Optimization, Darren R. Promer

Masters Theses

In this study a new technique is proposed for the determination of elastic-plastic stress-strain relations for isotropic materials using the force-displacement output from an instrumented indentation test, finite element simulation, and machine learning methods. This non-destructive testing methodology has promising potential for industry implementation. Applications to benefit from this method include the characterization of localized material properties on surface engineered components, and the post-manufacturing assessment of material properties for items such as additively manufactured metallic components and load-bearing welded joints.

Currently, the capability of the instrumented indentation test for determining material properties is limited to the elastic modulus and surface …