Engineering Commons^™

Predictive Models For Mechanistic Cutting Force Coefficients And Surface Roughness In Carbon Fiber Reinforced Polymers Milling With Tool Wear, Junbeom Son

Masters Theses

Machining carbon fiber composite materials poses significant challenges including rapid tool wear and decreased productivity. This research aims to address these challenges by developing a predictive model for surface roughness in carbon fiber composite milling operations using a cutting force-based approach.

This research applies a mechanistic cutting force model to force prediction in carbon fiber composite milling. Because tool wear can be significant in this application, the force model coefficients are defined as a function of the volume of material removed. This enables the cutting force growth with tool wear to be embedded within the model. Examples are provided for …

Cfrp Delamination Density Propagation Analysis By Magnetostriction Theory, Brandon Eugene Williams

All Dissertations

While Carbon Fiber Reinforced Polymers (CFRPs) have exceptional mechanical properties concerning their overall weight, their failure profile in demanding high-stress environments raises reliability concerns in structural applications. Two crucial limiting factors in CFRP reliability are low-strain material degradation and low fracture toughness. Due to CFRP’s low strain degradation characteristics, a wide variety of interlaminar damage can be sustained without any appreciable change to the physical structure itself. This damage suffered by the energy transfer from high- stress levels appears in the form of microporosity, crazes, microcracks, and delamination in the matrix material before any severe laminate damage is observed. This …

Life Cycle Energy Assesment Of Advanced Fiber Reinforced Composite Design And Manufacturing Methodologies, Urjit Lad

All Theses

Automotive industry at large is focused on vehicle light-weighting since a 6%-8% increase in fuel efficiency can be achieved with a 10% reduction in vehicle weight [1]. With the growing demand for cost-effective and sustainable light weighting of automobile structures, interest has increased in the application of fiber reinforced plastic (FRP) composites for use in the Body-in-White (BiW), which can account for up to 40% of the total vehicle weight. Traditional FRP composite manufacturing processes like vacuum assisted resin transfer molding, autoclave consolidation or use of automated fiber placement have been successfully used for marine and aerospace applications. However, these …

Effect Of Autoclave Process Parameters On Mechanical Behaviors Of Carbon Fiber Reinforced Polymer Composites Fabricated Via Additive Manufacturing, Quang Hao Nguyen

Honors Undergraduate Theses

Additively manufactured carbon fiber reinforced polymers (CFRP) are vastly studied for their remarkable mechanical properties compared to most other 3D printed materials. Different methods were employed to further increase mechanical performance of CFRP 3D printed parts. The objective of the study is to investigate the effect of autoclave postprocessing on the interlaminar shear behavior between 3D printed CFRP layers. 3D printed CFRP samples were processed with nine combinations of temperature and vacuum in an autoclave. Short beam shear (SBS) tests were performed to characterize the interlaminar shear strength (ILSS) of the samples after autoclave processing. Digital image correlation (DIC) was …

Numerical And Experimental Study Of Machining Process Of High Strength Lightweight Materials, Chao Zhang

All Dissertations

No abstract provided.

Post-Processing And Characterization Of Additive Manufactured Carbon Fiber Reinforced Semi-Crystalline Polymers, Patricia Revolinsky

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this work is to study the effect of post-processing on additive manufactured (AM) continuous carbon fiber reinforced plastics (CFRPs) performance. As-printed AM CFRPs do not perform as well as conventionally manufactured CFRPs with the same composition. Possible improvements to AM CFRP performance include annealing and applying uniaxial pressure with elevated temperature. Samples were subjected to pressure and temperature treatments and annealing at a constant temperature. Treated materials were subjected to three-point bending tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to characterize and assess sample performance. Results were assessed for flexural strength, …

Design And Analysis Of One-Piece 10” Carbon Fiber Wheels For Zips Racing Zr20 Formula Sae Racecar, Patrick Kruse, Henry J. Wathen, Jordan J. Hyde, Nicholas D. Dobben, Jordan D. Blake

Williams Honors College, Honors Research Projects

Reducing the weight of a vehicle in racing can substantially improve the vehicle dynamics and general performance capabilities. More specifically, the reduction of the unsprung corner weight can provide noticeable performance gains in handling and responsiveness, leading to a quicker, more agile car due to a lower yawing moment of inertia. Unsprung weight reduction also improves the car’s ability to maintain contact between the tires and the road surface for a more consistent grip. In this project we identified the loads that act on the wheel rims according to the data collected from the sensors in the car’s suspension, and …

Formula Sae Monocoque Chassis Development, Kc Egger, Brian Ford, Kyle Nagao, Neal Sharma, Donovan Zusalim

Mechanical Engineering

Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis.

A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque …

Finite Element Based Methodology To Predict Fatigue Compression Failure In Composite Based On Fiber Kinking Damage Model, Md Saddam Hossain

Mechanical and Aerospace Engineering Dissertations

Advanced polymer matrix composites are widely used in designing high-performance and lightweight spacecraft, rotorcraft, and automotive structures, due to its superior performance such as specific stiffness, specific strength, and toughness, which are appealing in reducing the weight of these structures. One critical factor that limits the efficient design of structures composed of fiber-reinforced composites (FRP) is the vulnerability of the material under compression loading since compressive strength of FRP material is typically a lot less compared to the tensile strength. Moreover, composite structure may undergo compression loading either by accidentally or by deliberately, large margins of safety are usually imposed …

Comparative Analysis And Dynamic Response Of Garolites Under Temperature Spectrum Using Low Velocity Impact Test, Birendra Chaudhary

Honors Theses

The purpose of this study was to examine the dynamic response of three different grades of garolites under the temperature spectrum. High-Temperature G-11 Sheet (HTG), Impact Resistance Garolite E-glass (HIG), and Economical Garolite (EG) were tested using an Instron Dynatup 8250 impact tester. Three specimens were used for all three composites and were tested at 6 different temperatures, -10^oC, 25^oC, 50^oC, 100^oC, 150^oC and 200^oC using the Low-Velocity Impact Machine with 20 Kip punch shear load cell. The results showed that HIG had the highest resistance to punch …

Finite Element Analysis Of Composite Aircraft Fuselage Frame, Aditya Milind Dandekar

Mechanical and Aerospace Engineering Theses

Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. …

Investigation Of Drilling Performance In Cryogenic Drilling On Cfrp Composite Laminates, Tian Xia

Theses and Dissertations--Mechanical Engineering

In recent years, there has been a substantial growth in the application of carbon fiber reinforced plastic (CFRP) composite materials in automobile and aerospace industries due to their superior properties such as lightweight, high strength, excellent corrosion resistance, and minimal fatigue concerns. The present study evaluates the drilling performance of woven carbon fiber reinforced plastics under both dry and cryogenic cooling conditions using uncoated solid carbide drill with a through-hole for coolant application.

The effects of the cooling conditions and the cutting parameters on drilling performance in drilling CFRP were evaluated in terms of generated thrust force, torque, cutting edge …