Structural fiber-reinforced polymer (FRP) composite materials consisting of a polymer matrix reinforced with layers of high-strength fibers are used in numerous applications, including but not limited to spacecraft, vehicles, buildings, and bridges. Researchers in the past few decades have suggested the necessary integration of sensors (e.g.
View Article and Find Full Text PDFPolymer concrete (PC) has been used to replace cement concrete when harsh service conditions exist. Polymers have a high carbon footprint when considering their life cycle analysis, and with increased climate change concerns and the need to reduce greenhouse gas emission, bio-based polymers could be used as a sustainable alternative binder to produce PC. This paper examines the development and characterization of a novel bio-polymer concrete (BPC) using bio-based polyurethane used as the binder in lieu of cement, modified with benzoic acid and carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs).
View Article and Find Full Text PDFTextile reinforced concrete (TRC) has gained attention from the construction industry due to its light weight, high tensile strength, design flexibility, corrosion resistance, and remarkably long service life. Some structural applications that utilize TRC components include precast panels, structural repair, waterproofing elements, and façades. TRC is produced by incorporating textile fabrics into thin cementitious concrete panels.
View Article and Find Full Text PDFMeasurement of bridge displacements is important for ensuring the safe operation of railway bridges. Traditionally, contact sensors such as Linear Variable Displacement Transducers (LVDT) and accelerometers have been used to measure the displacement of the railway bridges. However, these sensors need significant effort in installation and maintenance.
View Article and Find Full Text PDFPurpose: "Damage" is an engineering term defining a period between a state of material perfection and the onset of crack initiation. Clinically, it is a loss of fixation due to microstructural breakdown, indirectly measured as a reduction of stiffness of the bone-implant construct, normalized by the cross-sectional area and length of the bone. The purpose of this study was to characterize damage in a cadaver model of extra-articular distal radius fracture with dorsal comminution treated using 2-column volar distal radius plates.
View Article and Find Full Text PDFGlass fiber reinforced polymer (GFRP) composites are widely used in infrastructure applications including water structures due to their relatively high durability, high strength to weight ratio, and non-corrosiveness. Here we demonstrate the potential use of carbon nanoparticles dispersed during GFRP composite fabrication to reduce water absorption of GFRP and to enable monitoring of moisture damage propagation in GFRP composites. GFRP coupons incorporating 2.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2016
In this work, we report the potential use of novel carbon nanofibers (CNFs), dispersed during fabrication of glass fiber composites to monitor damage propagation under static loading. The use of CNFs enables a transformation of the typically non-conductive glass fiber composites into new fiber composites with appreciable electrical conductivity. The percolation limit of CNFs/epoxy nanocomposites was first quantified.
View Article and Find Full Text PDFObjectives: We performed a simple biomechanical study to compare the fixation strength of titanium mesh with traditional tension-band augmentation, which is a standard treatment for transverse patella fractures. We hypothesised that titanium mesh augmentation is not inferior in fixation strength to the standard treatment.
Methods: Twenty-four synthetic patellae were tested.
A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section.
View Article and Find Full Text PDFEntangled networks of carbon nanofibers are characterized both mechanically and electrically. Results for both tensile and compressive loadings of the entangled networks are presented for various densities. Mechanically, the nanofiber ensembles follow the micromechanical model originally proposed by van Wyk nearly 70 years ago.
View Article and Find Full Text PDFThis investigation examines the role of carboxyl functionalized multi-walled carbon nanotubes (COOH-MWCNTs) in the on- and off-axis flexure and the shear responses of thin carbon woven fabric composite plates. The chemically functionalized COOH-MWCNTs were used to fabricate epoxy nanocomposites and, subsequently, carbon woven fabric plates to be tested on flexure and shear. In addition to the neat epoxy, three loadings of COOH-MWCNTs were examined: 0.
View Article and Find Full Text PDFPurpose: Radial subluxation and cartilage thinning have been associated with initiation and accelerated development of osteoarthritis of the trapeziometacarpal joint. Few investigators have reported on the benefits of opening wedge trapezial osteotomy for altering the contact mechanics of the trapeziometacarpal joint as a possible deterrent to the initiation or progression of osteoarthritis. We used cadaveric specimens to determine whether opening wedge osteotomy of the trapezium was successful in reducing radial subluxation of the metacarpal base and to quantify the contact area and pressure on the trapezial surface during simulated lateral pinch.
View Article and Find Full Text PDFThe following is Part B of a two-part study. Part A evaluated, biomechanically, intramedullary (IM) nails versus locking plates for fixation of an extra-articular, metaphyseal wedge fracture in synthetic osteoporotic bone. Part B of this study introduces deterministic finite element (FE) models of each construct type in synthetic osteoporotic bone and investigates the probability of periprosthetic fracture of the locking plate compared with the retrograde IM nail using Monte Carlo simulation.
View Article and Find Full Text PDFThe following is a two-part study. Part A evaluates biomechanically intramedullary (IM) nails vs. locking plates for fixation of femoral fractures in osteoporotic bone.
View Article and Find Full Text PDFPurpose: Controversy exists over the pathologic anatomy of irreducible dorsal metacarpophalangeal (MCP) dislocation. The aim of this work is to develop a cadaveric model of MCP joint dislocation that closely simulates the clinical situation and to study the structures around the MCP joint and their contribution to irreducibility of the dislocation.
Methods: Nine fresh-frozen cadaveric specimens were amputated at the radiocarpal joint and stabilized in a specially formulated fixture.