Structures and Materials Commons^™

The Effects Of Damage Arrestment Devices In Composite Plate Sandwiches With Fastener Holes, Mark Anderson, Nancy Hung Choy, Lacey Jones, Rita Kourskaya

Aerospace Engineering

Composite materials such as a carbon fiber are used in a variety of new technologies including aircraft, spacecraft, and motor vehicles. Carbon fiber has a high strength to weight ratio, a key advantage over other material options. This report discusses the use of composite damage arrestment devices (DADs) in composite sandwich panels with a foam core. There are three different curing cycles tested for the DADs: pressure only, vacuum only, and vacuum with 1000 lbs of pressure. Using a Tetrahedron Heat Press to cure the composite specimen and an Instron Machine to perform tensile testing, data was collected for each …

Composite I-Beam Fabrication And Testing In Response To 14th Annual Sampe Bridge Competition, Kodi Rider, Niño Noel Las Piñas, Hans Mayta

Aerospace Engineering

Composites are a type of material that generally combines two materials yielding mechanical properties that are different than its constituent parts. These constituents are classified as either a fiber or a matrix. The objective of this project is to create a carbon-fiber composite I-beam that meets the specifications of the SAMPE student bridge competition. The I-beam consists of carbon fiber unidirectional and woven laminas, as well as aluminum honeycomb and high density polystyrene foam to stiffen the structure. The bridge contest rules limit the dimensions and weight of the bridge. The cross-section must be within 4 inches x 4 inches …

Design, Manufacturing And Testing Of An Environmentally-Green Bipropellant Thruster, Alex Bendoyro, Gabriel Sanchez, Erin Stearns, Phillip Takahashi

Aerospace Engineering

This project reviews the design, manufacturing and experimentation process of a green bi-propellant thruster designed to output 5 lbf. The goals were to successfully design, manufacture and test a thruster, while discovering the complications that arise through out the complete design process of a green thruster. The thruster was successfully designed using ideal rocket equations and the design was successfully confirmed using CFD and FEA. Manufacturing of the thruster was fully planned and revealed mild flaws in thruster design. For example some features were not manufacturable to the exact measurements desired. Testing of the engine gave results inconsistent with expected …

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …

Study Of The Effect Of Different Lay-Up Methods On The Composite Mechanical Characteristics, Veronica Cuevas, Walter Ely Salguero

Aerospace Engineering

The purpose of this experiment is to investigate and understand composite structures and the effect of different layup methods on the composite structure, particularly a composite I-beam. One must learn the procedure on how to build the composite I-beam and put it together then build the final composite I-beam and enter the I-beam in the 14^th Annual Society for the Advancement of Material and Process Engineering (SAMPE) Student Bridge Contest. The competition will be held May 25^th, 2011 in Long Beach, CA. The I-beam was entered in the competition and placed 4^th out of 5. The …

A Space Based Particle Damper Demonstrator, John Brown

Master's Theses

The structure and payload of a CubeSat flight experiment that investigates the performance of particle dampers in a micro-gravity environment was designed, built, and tested, and will provide on orbit data for model validation and improved performance predictions for space applications of particle damping.

A 3-D solid model of the integrated CubeSat structure and payload was created satisfying all constraints from CubeSat and the System Dynamics Department at Northrop Grumman Aerospace Systems. The model was verified using commercially available Finite Element Analysis software (FEA), and a prototype structure part was fabricated. The prototype was tested and verified the FEA. A …

The Effects Of A Damage Arrestment Device On The Mechanical Behavior Of Sandwich Composite Beams Under Four-Point Bending, Richard Anthony Davis

Master's Theses

The demand for an insert on composite sandwich structures to aid in the arrestment of face-core delamination is of great need.  This research studies the use of a damage arrestment device (DAD) that connects the carbon fiber face sheets to the foam core to find whether an increase in the structural integrity of the sandwich beam results.  Experimental analysis was employed to test the samples and was verified by a theoretical and finite element approach.

The mechanical properties of LTM45/CF1803 pre-impregnated carbon fiber and Last-A-foam FR 6710 polyvinylchloride foam were experimentally analyzed using ASTM D3039 and ASTM D1621 standards respectively …

Ultimate Compression After Impact Load Prediction In Graphite/Epoxy Coupons Using Neural Network And Multivariate Statistical Analyses, Alexandre David Grégoire

Doctoral Dissertations and Master's Theses

The goal of this research was to accurately predict the ultimate compressive load of impact damaged graphite/epoxy coupons using a Kohonen self-organizing map (SOM) neural network and multivariate statistical regression analysis (MSRA). An optimized use of these data treatment tools allowed the generation of a simple, physically understandable equation that predicts the ultimate failure load of an impacted damaged coupon based uniquely on the acoustic emissions it emits at low proof loads. Acoustic emission (AE) data were collected using two 150 kHz resonant transducers which detected and recorded the AE activity given off during compression to failure of thirty-four impacted …

Validation Of Proposed Metrics For Two-Body Abrasion Scratch Test Analysis Standards, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street

Publications

The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed “Zone of Interaction” (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width as currently defined by the ASTM G 171 Standard. The ZOI has been found to be at least twice the size of a standard width measurement, in some cases considerably greater, indicating that at least half of the disturbed surface …

X-51 Composite Airframe, Brendon J. Townshend

Aerospace Engineering

This paper gives an overview of the progress that has been made in the design build of the X-51.  The X-51 is a composite scale replica of a P-51D fuselage integrated with a P-51H wing.  Issues with the airframe as well as current action items are discussed, as well as findings so far in preliminary design.

A Shock Tube Technique For Blast Wave Simulation And Studies Of Flow Structure Interactions In Shock Tube Blast Experiments, Nicholas N. Kleinschmit

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Improvised explosive devices (IED’s) are widely used against US and allied forces fighting in Iraq and Afghanistan. Exposure to IED blast may cause blast-induced traumatic brain injury (bTBI). The injury mechanisms are however not well understood. A critical need in bTBI-related research is the ability to replicate the loading conditions of IED blast waves in a laboratory environment. In this work, experimental studies have been carried out to explore the use of the shock tube technique for generating air shock waves that mimic the temporal and spatial characteristics of free-field blast waves and to investigate the blast wave-test sample interactions …

Effects Of Prior Aging At 274⁰C In Argon On Inelastic Deformation Behavior Of Pmr-15 Polymer At 288⁰C: Experiment And Modeling, Joseph A. Wahlquist

Theses and Dissertations

No abstract provided.

Modeling And Preliminary Finite Element Analysis On The Spun Structure For The Cpintersep Project, Jason Carpenter, Kelly Cheng, Jeffrey Ma, Richard Pelham, Kevin Povey

Aerospace Engineering

This paper details the process of modeling and importing the model into FEA for the spun structure of the BS376 spacecraft. Engineering drawings were converted into 3D models using Pro/Engineer and then imported and into Patran for pre-processing of a Finite Element Model. To verify the Finite Element Model, several test cases were set up and solved using Nastran solver. Our simple load cases were found to be in congruence with analytical solution methods validating the finite element model.

Static And Fatigue Failure Response Of Woven Carbon Fiber Specimens With Double Edge Notches, Ahmad J. Amini

Master's Theses

Carbon fiber composites are continually seeing increased use in aerospace applications. It is necessary to understand their failure modes in order to properly design and perform analysis on structures constructed primarily from them. This thesis studies woven carbon fiber composites with and without double-edge notches in a series of static and fatigue tests performed on an Instron 8801 servo-hydraulic testing system.

Specimens were constructed of Advanced Composites Group product # LTM45EL woven carbon fiber pre-preg/epoxy and were cut to approximately 9-inch in length and 1-inch in width. Notches were cut into some of the specimens using a slitting saw blade …

The Effectiveness Of Damage Arrestment Devices In Delaying Fastener-Hole Interaction Failures In Carbon Fiber Polyurethane Foam Composite Sandwich Panels Subjected To Static And Dynamic Loading Under Increased Temperatures, Dominic E. Surano

Master's Theses

A study was conducted to investigate simple, cost-effective manufacturing techniques to delay skin-core delamination, micro-buckling and bearing stress failures resulting from fastener-hole interactions. Composite sandwich panels, with and without damage arrestment devices (DADs), were subjected to monotonic compression at a rate of 5mm per second, and compression-compression fatigue at 50% yield at an amplitude of 65%, under temperatures of 75, 100, 125, 150, 175, and 200 °F.

The sandwiches tested were composed of two-layer cross-weave carbon fiber facesheets, a polyurethane foam core, and an epoxy film adhesive to join the two materials. The most successful method to delay the aforementioned …

Descent Systems For An Improved And Reusable Gemini Capsule, Heather Pitts

Von Braun Symposium Student Posters

No abstract provided.

An Investigation Of Damage Arrestment Devices Application With Fastener/Hole Interaction, Richard Vincent S. Balatbat

Master's Theses

This thesis presents a parametric study on the effects of how damage arrestment devices application interacts with a fastener in a composite sandwich panel. The primary objective of the damage arrestment device was to prevent the failure of the composite face sheet, such as crack propagation, around the hole/fastener joint. The damage arrestment devices are made of composite strips that are inserted under the face sheet to increase the overall structural strength of the panel and to prevent the propagation of failure along the hole. This was supposed to be a quicker and stronger alternative to potted inserts for composite …

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus

Publications

Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement …

Matlab Structural Analysis Code For String Wing Box Structure, Sean Brown

Aerospace Engineering

This report outlines the method used for analysis of a wing box structure for the experimental “stringy” wing structure often used in light RC aircraft. This code is able to find the displacement of each joint, and the stress and forces in each member of the truss structure. It also has the features of load and structure visualization, Kevlar string removal, user-defined point and distributed loading functions, and user-defined failure criteria function. This method and resulting code is meant for use in the support of the Human Powered Helicopter project being undertaken by the Aerospace and Mechanical Engineering Department at …

Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent

Aerospace Engineering

California Polytechnic State University students designed, built, and certified ground support equipment for the Northrop Grumman Massive Heat Transfer Experiment. The Cal Poly design team built the 10000, 20000, and 30000 assemblies to meet Northrop Grumman requirements. The requirements included interface limitations, design load factors, delivery, and testing specifications. The design process consists of requirements generation, conceptual design, preliminary design, design reviews, manufacturing, and certification. The hardware was successfully completed and is used at the Johnson Space and Kennedy Space Center.