A5083605431- Fatigue and fracture mechanics
- Welding Techniques and Residual Stresses
- Advanced Fiber Optic Sensors
- Advanced Surface Polishing Techniques
- Advanced machining processes and optimization
- Photonic and Optical Devices
- Non-Destructive Testing Techniques
- Ultrasonics and Acoustic Wave Propagation
- Mechanical Behavior of Composites
- Advanced MEMS and NEMS Technologies
- Engineering Structural Analysis Methods
- Semiconductor Lasers and Optical Devices
- Microstructure and Mechanical Properties of Steels
- High Temperature Alloys and Creep
- Elasticity and Material Modeling
- Optical measurement and interference techniques
- High-Velocity Impact and Material Behavior
- Structural Load-Bearing Analysis
- Metal Forming Simulation Techniques
- Material Properties and Failure Mechanisms
- Hydrogen embrittlement and corrosion behaviors in metals
- Tribology and Wear Analysis
- Laser Material Processing Techniques
- Epoxy Resin Curing Processes
- Marine Biology and Environmental Chemistry
Stanford University
2007-2021
Cabot (United States)
2002
Materials Science & Engineering
1988
General Electric (United States)
1980
Caterpillar (United States)
1971
Critical considerations in engineering biomaterials for rotator cuff repair include bone-tendon-like mechanical properties to support physiological loading and biophysicochemical attributes that stabilize the site over long-term. In this study, UV-crosslinkable polyurethane based on quadrol (Q), hexamethylene diisocyante (H), methacrylic anhydride (M; QHM polymers), which are free of solvent, catalyst, photoinitiator, is developed. Mechanical characterization studies demonstrate polymers...
The principle of operation a multi-parameter dual Bragg grating fiber optic sensor formed in polarization maintaining is described. response the to separately applied longitudinal loading, transverse loading and temperature change presented terms wavelength shifts peaks. Results those tests are used as calibration data. A model predict two orthogonal strain components from measured peaks observed combined based on an assumed linear behavior between loadings uses data input. Predictions...
In this paper, we present a method to measure two components of transverse strain in an optical fiber using single Bragg grating written into high-birefringent, polarization- maintaining (PM) fiber. The reflected spectrum from contains peaks corresponding the orthogonal polarization modes If axial and temperature is known, then can be computed changes wavelength peaks. A near 1300 nm PM was loaded diametrical compression, were monitored analyzer. Transverse strains available strain-optic...
Fiber optic grating sensors written into polarization preserving optical fiber may be used to monitor multidimensional strain fields in composite materials. This paper provides an overview of the characterization and test multiaxis formed by writing 1300 1550 nm gratings fiber. A discussion usage these measure two three dimensional will made. brief review practical applications technology shear strain, transverse gradients as well axial traverse made with emphasis on aerospace civil...
Wave-swept macroalgae are subjected to large hydrodynamic forces as each wave breaks on shore, loads that repeated thousands of times per day. Previous studies have shown can easily withstand isolated impositions maximal field forces. Nonetheless, break frequently. Here we investigate the possibility loading by sub-lethal eventually cause fracture fatigue. We determine toughness, in form critical strain energy release rate, for several flat-bladed macroalgae, thereby assessing their...
This paper presents predictions of fatigue crack initiation life for three distinctly different, irregular load histories, each applied to keyhole-notched compact tension specimens at several maximum levels and using two different structural steels. Three computerized prediction methods (Landgraf, Wetzel, a Nominal Stress Range approach) are used. All based on histories condensed 10% their original number reversals by the Racetrack Method. method, which is described in detail, selects most...
Holographic-hole drilling is a method developed for the rapid determination of residual stresses from an optical interference fringe pattern. A small diameter blind hole drilled into part containing stresses, and displacements caused by localized stress relief are registered real-time holographic interferometry. The resulting pattern evaluated to calculate using simple 'fringe counting' described here. Results applying in laboratory tests variety uniform biaxial states-of-stress equibiaxial...
A method to determine process-induced residual stress in fiber-reinforced composite materials using strain measurements from embedded fiber optic sensors is presented. This allows non-destructive, real-time determination of macrostress these and may be useful for both process monitoring control. Extrinsic Fabry-Perot interferometer were Hercules AS4/3501-6 graphite/epoxy specimens prior cure. The cured a press, the internal strains temperatures developed during processing monitored recorded....
Abstract Residual stresses are created in engineering components during fabrication and processing. Such can strongly influence structural behavior. They generally found by experimental means. A widely used way of finding residual is removal a small volume material containing measurement the strains that develop surrounding as result being released. The then be to compute stresses. Drilling shallow hole most common implementing this approach, with measured nearby strain gages adhered...
The low-to-intermediate cycle fatigue behavior of A533B steel is investigated using solid round bar specimens tested in combined bending and torsion. Loadings are applied in-phase 90 deg out-of-phase to produce cases proportional nonproportional biaxial fatigue. Out-of-phase loadings found be more damaging than loadings. Two equivalent strain criteria similar those the ASME Boiler Pressure Vessel Code a newer approach based on cyclic plastic work used correlate lives. underestimate damage...