Engineering Commons^™

Evaluations Of Frp Composite Coupons Under Impact And Puncture, Lekhnath Bhandari

Graduate Theses, Dissertations, and Problem Reports

Evaluations of FRP Composite Coupons Under Impact and Puncture

Lekhnath Bhandari

Railroad tank cars are the main mode of transportation for carrying flammable liquids and other hazardous materials, in any mode of ground transportation system. These tank cars, if punctured during derailments may explode releasing large amounts of hazardous materials and posing serious threats to human life and leading to economic losses. To minimize such catastrophes, in 2015, United States Department of Transportation (USDOT) proposed to improve the thermal and puncture performances of these tank cars and introduced two new design specifications: DOT-117 and DOT-117R. Tank cars with 9/16 inches …

Experimental And Design Evaluation Of Multi-Bolted Gfrp Joints, Amir Hossein Houshmandyar

Graduate Theses, Dissertations, and Problem Reports

For infrastructure system implementation, high strength/stiffness to self-weight ratio, corrosion resistance and ease of fabrication are just a few of the many advantages of pultruded fiber reinforced polymer (PFRP) composites over traditional construction materials. However, challenges of engineered FRP materials are addressed via continuous updating of design codes. For example, the anisotropic nature of FRP composite materials includes different mechanical properties in different directions (pull or longitudinal direction vs. transverse to pull direction) of a structural member, resulting in design complexities over isotropic materials. Typically, infrastructure systems are built by bolting FRP structural members because of certain advantages of bolted …

Retrofit Of Corroded Corrugated Metal Culverts Using Gfrp Slip-Liner, Rahulreddy Chennareddy

Civil Engineering ETDs

Culverts are water conveyance structures, typically used to allow water flow and maintain a balance between the flow streams without interrupting structures such as highways and bridges. Corrugated metal pipes (CMPs) have been used as culverts in North America since the 1950s because of their low cost and simple construction method. Today, the corrosion of CMPs is a major problem faced by all U.S. Departments of Transportation. There is an urgent need to provide an efficient solution, one that is corrosion-resistant, to retrofit thousands of corroded CMPs across the country. High specific strength, high strength to weight ratio, corrosion resistance, …

Structural Health Monitoring Of Composite Parts: A Review, Jacob Pessin

Honors Theses

Structural health monitoring has the potential to allow composite structures to be more reliable and safer, then by using more traditional damage assessment techniques. Structural health monitoring (SHM) utilizes individual sensor units that are placed throughout the load bearing sections of a structure and gather data that is used for stress analysis and damage detection. Statistical time based algorithms are used to analyze collected data and determine both damage size and probable location from within the structure. While traditional calculations and life span analysis can be done for structures made of isotropic materials such as steel or other metals, composites …

Bending Response Of Timber Mortise And Tenon Joints Reinforced With Filler-Modules And Frp Gussets, Andrew Robert Pacifico

Graduate Theses, Dissertations, and Problem Reports

In 2013, the California Bay Area (CBA) passed a set of ordinances to ensure that their 10,000 plus timber soft-story buildings were prepared for seismic events, through nondestructive evaluation methods. Many property owners are searching for an affordable retrofitting system that will also meet CBA’s new laws focusing on installations by the mandated deadlines in 2020. Over the past three to four decades, Fiber Reinforced Polymer (FRP) composites have found their way into the civil infrastructure sector for rehabilitation. The objective of this study is to evaluate the bending behavior retrofitted mortise and tenon timber joints reinforced with engineered wood …

Short Beam Shear Strength Evaluations Of Gfrp Composites: Correlations Through Accelerated And Natural Aging, William Todd Barker

Graduate Theses, Dissertations, and Problem Reports

Fiber Reinforced Polymers (FRP) composites have been materials of interest in replacing or reinforcing steel, wood, and concrete, but lack of understanding of degradation under physical and chemical aging is a main concern. Through many years of research, the understanding of aging or durability of GFRPs has improved. To be able to evaluate aging related degradation rates, an accelerated aging methodology under varying environments is introduced. Accelerated aging is a concept used to age composites in a lab controlled environment under varying pH conditions (2 to 13) and temperatures (~ -20° to +160°F). Once acceleratedly aged testing is completed, Arrhenius …

The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney

Master's Theses

While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …

Apparent Porosity And Compressive Strength Of Heat-Treated Clay/Iron Sand/Rice Husk Ash Composites Over A Range Of Sintering Temperatures, M. Nizar Machmud, Zulkarnain Jalil, Mochammad Afifuddin

Makara Journal of Technology

Novel composites of clay/iron sand/rice husk ash (RHA) have been developed. Electric furnace was used to perform heat treatment on the composites to study the effect of sintering temperature on their apparent porosity and compressive strength. Two types of RHA with different bulk density were prepared to gain an understanding of the influence of apparent porosity on compressive strength of the heat-treated composites over a range of sintering temperatures. Heattreated composites, made of clay/iron sand and clay/RHA, were also prepared as a referenced material. X-ray diffraction (XRD) analysis was further performed to comprehensively discuss the role of iron sand on …

Modeling Of Debonding And Crack Propagation In Fibrous Composites Using A Discontinuous Galerkin Approach, Wesley Michael Hicks

Masters Theses

A recently proposed Discontinuous Galerkin (DG) method for modeling debonding and fracture within the context of the finite element method is investigated for problems relating to fiber reinforced composites, namely fiber-matrix interfacial debonding which progresses to matrix fracture. The results are then compared against an existing intrinsic cohesive zone method and a hybrid Discontinuous Galerkin method. The results show that the method can eliminate the problem of artificial compliance that is associated with intrinsic cohesive zone models. Eliminating this stiffness has the positive effect of removing user-defined numerical parameters that are not actually present in the physical system. A key …

Geopolymer Concrete-Filled Pultruded Composite Beams – Concrete Mix Design And Application, Wahid Ferdous, Allan Manalo, Amar Khennane, Obada Kayali

Wahid Ferdous

The limited research on the geopolymer concrete mix design for targeting a specific strength is identified an obstacle for their effective design and wide use. In this paper, a mix design procedure has been proposed for fly-ash based geopolymer concrete and its use as infill hybrid composite beam is investigated. Then, the structural performance of geopolymer concrete filled hybrid composite beam is investigated to determine their possible application in civil infrastructure. Firstly, a detailed procedure of mix design for fly-ash based geopolymer concrete is presented. Secondly, three hybrid beams filled with geopolymer concrete were prepared and tested in a four-point …

Composite Railway Sleeper: A Cost Effective And Eco-Friendly Alternative, Wahid Ferdous, Allan Manalo, Thiru Aravinthan, Gerard Van Erp

Wahid Ferdous

High maintenance cost, huge carbon-dioxide emission from cement and steel industries and early failures of the traditional timber, concrete and steel sleepers motivated the composite sleepers as an alternative to replace those in the existing rail track. This poster presented the optimised composite railway sleeper concept and their static performance in laboratory scale. Results found that the optimised shape can reduce two-third volume of materials from the traditional rectangular shape and their behaviour is comparable with timber sleeper.

Benefits Of Geopolymer Concrete-Filled Frp Beams And Its Flexural Behavior, Wahid Ferdous, Allan Manalo, Amar Khennane, Obada Kayali

Wahid Ferdous

Structural Optimisation Of Composite Railway Sleeper, Wahid Ferdous, Allan Manalo, Gerard Van Erp

Wahid Ferdous

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

Investigation Of Composite Patch Performance Under Low-Velocity Impact Loading, Geoffrey Roy Goodmiller

Masters Theses

Bonded fiber composite repair on damaged metal structures can be an effective method to restore load carrying capacity or increase damage resistance. Low velocity impacts can cause barely visible damage to the interior structure of laminated composites. Delamination between plies is of particular concern in these composites. Impacts may also create disbonds between the patch and metal substrate. A building-block approach was suggested to model impact damage to composite patches. Composite, adhesive, and metal substrate damage models were separately validated and then combined. Cohesive Zone theory modeled interlaminar composite damage and adhesive damage. Hashin failure criteria with energy dissipation based …

An Automated Finite Element Analysis Framework For The Probabilistic Evaluation Of Composite Lamina Properties, Jonathan Phillips Weigand

Masters Theses

This thesis outlines the development of computational modeling tools used to predict the elastic properties of composite lamina from representative volume elements (RVE) using numerical methods. The homogenization approach involves the use of Gauss’s Theorem to simply the average volumetric strain integral into a surface integral containing which is defined by surface displacements and their direction. Simulations of RVEs under specific loading conditions (longitudinal tension or shear and transverse tension or shear) are then performed in the software package ABAQUS to obtain the surface displacements. It was found that obtaining quality meshes and applying periodic boundary conditions for each RVE …

Hybrid Frp-Concrete Railway Sleeper, Wahid Ferdous, Amar Khennane, Obada Kayali

Wahid Ferdous

The aim of this research was to investigate the feasibility of a hybrid FRP-concrete beam as a rail sleeper. It was hoped that the new design would overcome some of the sustainability issues associated with traditional sleepers. The hybrid system consisted of a Rectangular Hollow Section (RHS) pultruded profile filled with geo- polymer concrete. The specimens were tested in a four-point bending setup to determine the flexural properties such as the bending modulus (E) and modulus of rupture (MOR). It was found that the proposed composite beam satisfied the minimum flexural requirements for composite railway sleepers as stated in the …

Static Flexural Behaviour Of Fly Ash-Based Geopolymer Composite Beam: An Alternative Railway Sleeper, Wahid Ferdous

Wahid Ferdous

These days, the most commonly used materials for railway sleepers are timber, concrete and steel. High maintenance cost, installation issues, deterioration of materials, and environmental considerations are among the factors that prompt research and industry to seek a different and more efficient system. This research was undertaken with the aim of developing a material for sleepers which may overcome some of these problems. Through a comprehensive survey of the literature, it was decided to propose and investigate a sleeper system composed of fly ash-based geopolymer concrete and pultruded FRP profile composites. Although the engineering properties of fly ash-based geopolymer concrete …

Failure Analysis Of Impact-Damaged Metallic Poles Repaired With Fiber Reinforced Polymer Composites, Robert Arthur Slade

Electronic Theses and Dissertations

Metallic utility poles, light poles, and mast arms are intermittently damaged by vehicle collision. In many cases the vehicular impact does not cause immediate failure of the structure, but induces localized damage that may result in failure under extreme service loadings or can promote degradation and corrosion within the damaged region. Replacement of these poles is costly and often involves prolonged lane closures, service interruption, and temporary loss of functionality. Therefore, an in situ repair of these structures is required. This thesis examines the failure modes of damaged metallic poles reinforced with externally-bonded fiber reinforced polymer (FRP) composites. Several FRP …

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 …