Consultant, Kevin Kennedy Associates Inc.
Providing mechanical engineering, residual stress measurement, life prediction, fracture mechanics, crack propagation, failure analysis, forensic engineering and related expertise to a variety of clients.
Engineering Analysis Consultant
Developed a new approach to compute stress intensity factors for both 2-D and 3-D bodies. The approach applies to a crack of arbitrary front and computations can be carried out by the finite element method without using crack elements or very fine mesh near the crack tip. Developed new methods for measurement of residual stress distributions in different configurations of welds. Derived analytical solutions for the vibration of the U-bend tube bundle in cross-flow, which can be used for the prediction of, wear and fatigue failure in stream generator tubes. Analysis and prediction of the fatigue fracture for a U-bend tube in a steam generator. Developed a model to predict the strength of glass due to subsurface flaws. Prediction of ductile fracture initiation in an experimental pressure vessel. Development of a model to predict stress concentration in a longitudinal welded pipe under creep conditions. Prediction of the influence of residual stresses due to shot peening on both the detection of fatigue cracks and their propagation in a titanium compressor disk. Prediction of burst pressure in a pipe due to plastic deformation in a region with reduced thickness. Analysis of the strain rate effect on the plastic instability. Prediction of the instability due to the creep deformation of a rotating part made by zinc-die-casting.
Engineering Measurements Consultant
Measurement of residual stresses in various configurations. Experience included water quenched cylinders, laser treated parts, sandwich-brazed plates, hardsurfaced specimens with different geometries, omega-shaped ring welded on steel blocks, gas-tungsten arc welded plate, bearing groove of axles, pyrolytic carbon-coated graphite leaflet in cardiac devices, pyrolytic carbon-coated graphite valve housing in cardiac devices, clad parts, shot peened surface, near surface residual stresses due to fire damage, measurement of dynamic response due to controlled explosions, measurement of the deformation of pressurized natural gas pipes, measurement of stresses of water beds, measurement of cracking of glass due to indenting and scribing.
Computer Programming and Applications Consultant
Developed programs for flange stress analysis using a FEM engine, graphic mapping of laser scanned drum surface, computation of transient hydraulic response, digitizing graphic data, residual stress measurement for the slitting method using analytical solutions or 2-D finite element method, residual stress measurement for the single-slice method using 3-D finite element method, Finite element calculation of the effect of creep on burst pressure of piping at elevated temperature, 3-D finite element computation for the fracture analysis of a glass container, Finite element computation for wafer heating by electron beams, Finite element analyses of the magnetic field of a housing chamber, 3-D finite element computations for residual stresses due to different initial strain fields. Created a database for creep deformation. Provided analysis of the deformation of water beds.
Failure Analyses and Numerical Computations Consultant
Experience included prediction of ductile fracture initiation in an experimental pressure vessel, development of a model to predict stress concentration in a longitudinal welded pipe under creep conditions, prediction of the influence of residual stresses due to shot peening on both the detection of fatigue cracks and their propagation in a DC-10 titanium compressor disk, and calculation of effect of creep on burst pressure of piping at elevated temperature.
Assistant Research Engineer, Engineering College, U.C., Berkeley
Developed a new method for residual stress measurement based on solutions from fracture mechanics. Developed a model to predict the strength of glass due to subsurface flaws.
Research Associate, Department of Mechanical Engineering, U.C.
Developed a computational model for the failure analysis of a pressure vessel due to both internal pressure and thermal stresses; analytical and experimental studies of brittle/ductile transitions in brittle solids.
Assistant Professor, Dept. of Eng. Mechanics for Shanghai Jiao Tong University, Shanghai, China
Strength of Materials; Colloquium - Current research and teaching activities in engineering colleges in U.S.A. Tour lecture: the Compliance Method for residual stress measurement, Northwest Polytech. Institute, Xian, China. Computer system management: established communication between DEC-VAX and IBM PC; produced a supervising software for system management on a DEC-VAX.
Postdoctoral Research, Lawrence Berkeley Laboratory, Berkeley, CA
Analysis of micro-cracking in brittle materials due to scribing.
Teaching Assistant, Department of Mechanical Engineering for University of California, Berkeley, CA
Fracture Mechanics
