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Full-Text Articles in Engineering
Weibull Model Development For Fatigue Crack Growth, Bobby Day, Tarun Goswami
Weibull Model Development For Fatigue Crack Growth, Bobby Day, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
This effort is an attempt to "Weibullize" fatigue crack growth rate data as a function of stress intensity range (ΔΚ). It is not a classical Weibull application in that it does not address a population but rather treats rate of crack growth as a fraction of the highest rate of crack growth rate in the data set (usually the final data point of the set) as the "failed fraction of a population." All da/dN values are converted to a percentage or fraction of the 100% data value, processed into a linear relationship and plotted against the natural log of the …
A Review Of Nanotechnology Applications, Nick Ledbetter, Tarun Goswami
A Review Of Nanotechnology Applications, Nick Ledbetter, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
A review of current technology research efforts has been conducted in this paper. In nanoscience, objects are measured in nanometers, 1 billionth of a meter. For comparison, a human hair is approximately 100,000 nanometers thick and the smallest feature on current computer chips measures about 200 nanometers. Since nanotechnology has a wide range of applications from computer chip manufacturing, new materials, renewable energy, interconnection technology to mount the nano-chips, and in medical science, this review presents a broad summary of development efforts in the government and private sector laboratories. Therefore this project on the one hand prepares a review of …
A Window-Based Software For Fatigue Crack Growth Data Reduction, B. Keeton, Tarun Goswami
A Window-Based Software For Fatigue Crack Growth Data Reduction, B. Keeton, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
The objective of this research is to develop a Windows-based program to present the fatigue crack growth rate and mode I stress intensity factor range data. Microsoft Visual Basic was used to write the code. The program developed in this study calls out the input data in terms of crack length (α) and the number of cycles (Ν). Secant and seven point polynomial distribution was used to fit the data. The installation procedure for the program was copied onto a disk to install the program. Future work is needed to further modify the a-N data and therefore to present da/dN-ΔΚ …
Dwell Sensitivity Behavior And Modeling, E. Pyburn, Tarun Goswami
Dwell Sensitivity Behavior And Modeling, E. Pyburn, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
Since engineering materials are exposed to dwell-times in service, it is important to understand the effects of dwell times on the fatigue life. The mechanisms controlling deformation and failure under dwell conditions are in terms of metallographic damage namely; transgranular fracture, intergranular fracture, mixed intergranular transgranular fracture modes, surface striated damage, creep damage and oxidation. These mechanisms are very difficult to include in a quantitative model to predict the dwell sensitivity behavior of high temperature materials. Published creep-fatigue data were compiled from various sources for a number of materials such as copper alloys (NARloy-Z, AMZ1RC), steel alloys (9Cr-lMo), and nickel …
Failure Modes Of Biomedical Implants, Andrew Gratton, Bert Buford, Tarun Goswami, Dana Gaddykurten, Larry Suva
Failure Modes Of Biomedical Implants, Andrew Gratton, Bert Buford, Tarun Goswami, Dana Gaddykurten, Larry Suva
Biomedical, Industrial & Human Factors Engineering Faculty Publications
The metallic biomaterials are very well known among various biomaterials. Stainless steel was used successfully as an implant material in the surgical field, then Vitallium, cobalt based alloys were used as implant materials. Titanium is the newest metallic biomaterial among three main metallic biomaterials, stainless steels, Co-based alloys and titanium alloys. These materials are used for the instrumentation replacing failed hard tissue, for example, artificial hip joints, artificial knee joints, bone plates, dental implants and in similar applications. Biocompatibility characteristics of titanium alloys make it the preferred choice for such applications, additional factors being light weight, excellent mechanical properties, corrosion …
Creep-Fatigue Life Prediction Of Low Alloy Steels, James Toland, Tarun Goswami
Creep-Fatigue Life Prediction Of Low Alloy Steels, James Toland, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
The creep-fatigue behavior of Cr-Mo steels has been examined from published data. The published data were compiled in an earlier effort and used in this paper to develop a multivariate best-fit equation to predict the low cycle fatigue life. The fatigue test temperatures were representative of temperatures experienced in nuclear power plants, which varied from room temperature to 600°C. Within this temperature range, depending upon the test parameters used, creep and fatigue processes interact and failure occurs in the lowcycle fatigue regime.
Effect Of Exposure Time On The Fatigue Crack Growth Behavior Of Aircraft Skin Material, Kathryn Lemasters, Tarun Goswami
Effect Of Exposure Time On The Fatigue Crack Growth Behavior Of Aircraft Skin Material, Kathryn Lemasters, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
The objective of this research project is to identify the effects of service exposure on aircraft materials. The senior author participated in the KC-135 Corrosion Prevention Program conducted by the University of Utah, Salt Lake City. Data from this research program was analyzed to compare the fatigue crack growth rates of aged aircraft materials with those of virgin materials. 2024-T3(clad) Middle Tension (M(T)) specimens were machined from the fuselage and upper wing skins of a retired aircraft. Fatigue crack growth rate (da/dN) and mode 1 stress intensity factor range (Δ K) plots were generated for both sets of data. The …
Statistical Modeling Of Fatigue Crack Growth, Ignacio Guerra, Tarun Goswami
Statistical Modeling Of Fatigue Crack Growth, Ignacio Guerra, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
The objective of this research is to fit normal and lognormal distributions to fatigue crack growth rate (da/dN) data and present the data in terms of cumulative frequency distribution (f (x)) and a variant of da/dN and mode I stress intensity factor range (ΔΚ), z. The probability density functions (F(da/dN)) were also plotted for the data. The data was compiled from open literature, conducted on a hot section turbine disk material Inconel 718 under a North Atlantic Treaty Organization (NATO) project, through the Advisory Group on Aerospace Research and Development (AGARD). Incomel 718 was tested at 650°C utilizing various specimen …
Life Prediction Of Stainless Steels Used In Nuclear Reactors, Jonathan Clark, Tarun Goswami
Life Prediction Of Stainless Steels Used In Nuclear Reactors, Jonathan Clark, Tarun Goswami
Biomedical, Industrial & Human Factors Engineering Faculty Publications
Effects of dwell times and temperature on creep-fatigue behavior of stainless steels have been examined from published data. The temperatures of these materials varied from 430°C to 816°C. Within this temperature range creep and fatigue processes interact and failure occurs in the low-cycle regime. A least square best fit equation was developed from the compiled data fitting all the data points. The variables were temperature, strain rate, dwell time and strain range and were used with and without transformation functions to derive the equation. Statistical analysis was performed showing a very high coefficient of correlation value for the life prediction …