Structural Engineering Commons^™

Performance Evaluation Of Composite Utility Structures Under Wildfires And Mitigation Methods, Siddhant Sitoula

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Fiber Reinforced Polymer (FRP) composite utility poles and crossarms have been getting wider attention from the utility industries because of their advantages over the traditional wooden, concrete, and steel poles. Wood is vulnerable to fire, rot, and animal damage. Concrete poles are heavier, increasing both transportation and installation costs of the poles, in addition to limited-service life (40-50 years). Similarly, steel poles have durability and safety concerns because of their inherent corrosive nature and conductivity. These disadvantages are significantly reduced by the use of FRP composites in utility structures because of FRP’s strength, specific gravity, flexibility, non-conductivity and durability …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 (ETD)

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, …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 (ETD)

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 …

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% …

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 …