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Full-Text Articles in Engineering
The Quasi-Static And Cyclic Fatigue Fracture Behavior Of An Emerging Titanium Alloy, Kannan Manigandan, Tirumalai Srivatsan, Gregory Morscher
The Quasi-Static And Cyclic Fatigue Fracture Behavior Of An Emerging Titanium Alloy, Kannan Manigandan, Tirumalai Srivatsan, Gregory Morscher
Dr. Gregory N. Morscher
Sustained research and development efforts culminating in the emergence of new and improved titanium alloys have provided both the impetus and interest for studying their mechanical behavior under the extrinsic influence of loading spanning both static and dynamic. In this article, the quasi-static and cyclic fatigue fracture behavior of a titanium alloy (Ti-Al-V-Fe-O2) is highlighted. Test specimens of this titanium alloy were deformed both in quasi-static tension and cyclic stress amplitude–controlled fatigue. The quasi-static mechanical properties, cyclic fatigue response and microscopic mechanisms contributing to deformation and eventual fracture are highlighted in light of the competing and mutually interactive influences of …
Modeling Of Electromechanical Behavior Of Woven Sic/Sic Composites, Xhenhai Xia, Thanyawalai Sujidkul, Jianbing Niu, Craig Smith, Gregory Morscher
Modeling Of Electromechanical Behavior Of Woven Sic/Sic Composites, Xhenhai Xia, Thanyawalai Sujidkul, Jianbing Niu, Craig Smith, Gregory Morscher
Dr. Gregory N. Morscher
A coupled electro-mechanical model was developed to predict the mechanical behavior of woven SiC/SiC ceramic matrix composites and electrical resistance response to mechanical damages in the composites. The matrix is explicitly included in the model such that the matrix cracking and fiber break can be linked to the electrical resistance change during loading. The results show that the electrical resistance increases linearly with an increase of matrix crack density and the number of fiber breaks. The predictions are compared to the experimental results on 2D woven SiC/SiC ceramic composites. With proper materials parameters input, the models can accurately predict the …
Electrical Resistance Of Sic Fiber Reinforced Sic/Si Matrix Composites At Room Temperature During Tensile Testing, Gregory Morscher, Christopher Baker, Craig Smith
Electrical Resistance Of Sic Fiber Reinforced Sic/Si Matrix Composites At Room Temperature During Tensile Testing, Gregory Morscher, Christopher Baker, Craig Smith
Dr. Gregory N. Morscher
The implementation of Ceramic Matrix Composites necessitates the understanding of stress-dependent damage evolution. Toward this goal, two liquid silicon infiltrated SiCf reinforced SiC composites were tensile tested with electrical resistance (ER) monitoring as well as acoustic emission to quantify matrix cracking. ER was modeled using a combination of resistors in series and parallel to model transverse matrix cracks and fiber/matrix segments between matrix cracks. It is shown that resistance change is sensitive to transverse matrix crack formation and stress-dependent debonding length. The model appears to be accurate up to the stress for matrix crack saturation.
Electrical Resistance Monitoring Of Damage And Crack Growth In Advanced Sic-Based Ceramic Composites, Gregory Morscher, Craig Smith, Emmanuel Maillet, Chris Baker, Rabih Monsour
Electrical Resistance Monitoring Of Damage And Crack Growth In Advanced Sic-Based Ceramic Composites, Gregory Morscher, Craig Smith, Emmanuel Maillet, Chris Baker, Rabih Monsour
Dr. Gregory N. Morscher
No abstract provided.
Waveform-Based Selection Of Acoustic Emission Events Generated By Damage In Composite Materials, Emmanuel Maillet, Gregory Morscher
Waveform-Based Selection Of Acoustic Emission Events Generated By Damage In Composite Materials, Emmanuel Maillet, Gregory Morscher
Dr. Gregory N. Morscher
Acoustic emission (AE) has been shown to be a promising health monitoring technique for composite materials as it allows real-time location and identification of damage. When attempting to relate the recorded acoustic emission to a material׳s mechanical behavior, the relevance of results relies on an accurate selection of AE originating from material damage. Indeed, during mechanical tests most of the recorded AE is generated outside of the volume of interest and without proper filtering these AE signals can significantly affect the analysis. To date, there exists no common procedure for the selection of AE signals and therefore results can hardly …
Reduced-Order Multiscale-Multiphysics Model For Heterogeneous Materials, Zheng Yuan, Tao Jiang, Jacob Fish, Gregory Morscher
Reduced-Order Multiscale-Multiphysics Model For Heterogeneous Materials, Zheng Yuan, Tao Jiang, Jacob Fish, Gregory Morscher
Dr. Gregory N. Morscher
A unified coupled multiscale mechano-diffusion-reaction model of environmental degradation of polymer matrix composite (PMC) and ceramic matrix composite (CMC) is developed. The unified multiscalemultiphysics model couples multiple physical processes at multiple scales, including oxygen diffusion, oxidation, and deformation. The salient feature of the unified multiscalemultiphysics model is its computational efficiency accomplished through a systematic model reduced carried out prior to nonlinear analysis. The model has been validated for PMR-15 reinforced carbon fiber composite and melt infiltrated CMC-NASA N24A material system.
Experimental And Fem Study Of Thermal Cycling Induced Microcracking In Carbon/Epoxy Triaxial Braided Composites, Chao Zhang, Wieslaw Binienda, Gregory Morscher, Richard Martin, Lee Kohlman
Experimental And Fem Study Of Thermal Cycling Induced Microcracking In Carbon/Epoxy Triaxial Braided Composites, Chao Zhang, Wieslaw Binienda, Gregory Morscher, Richard Martin, Lee Kohlman
Dr. Gregory N. Morscher
The microcrack distribution and mass change in T700s/PR520 and T700s/3502 carbon/epoxy braided composites exposed to thermal cycling was evaluated experimentally. Acoustic emission was utilized to record the crack initiation and propagation under cyclic thermal loading between −55 °C and 120 °C. Transverse microcrack morphology was investigated using X-ray computed tomography. The differing performance of two kinds of composites was discovered and analyzed. Based on the observations of microcrack formation, a meso-mechanical finite element model was developed to obtain the resultant mechanical properties. The simulation results exhibited a decrease in strength and stiffness with increasing crack density. Strength and stiffness reduction …
Correlating Electrical Resistance Change With Mechanical Damage In Woven Sic / Sic Composites: Experiment And Modeling, Thanyawalai Sujidkul, Craig Smith, Zhijun Ma, Gregory Morscher, Zhenhai Xia
Correlating Electrical Resistance Change With Mechanical Damage In Woven Sic / Sic Composites: Experiment And Modeling, Thanyawalai Sujidkul, Craig Smith, Zhijun Ma, Gregory Morscher, Zhenhai Xia
Dr. Gregory N. Morscher
Silicon carbide (SiC) fiber-reinforced SiC matrix composites are inherently multifunctional materials. In addition to their primary function as a structural material, the electric properties of the SiC/SiC composites could be used for the sensing and monitoring of in situ damage nucleation and evolution. To detect damage and use that information to further predict the useful life of a particular component, it is necessary to establish the relationship between damage and electrical resistance change. Here, two typical SiC/SiC composites, melt infiltrated (MI), and chemical vapor infiltrated (CVI) woven SiC/SiC composites, were tested to establish the relationship between the electrical response and …
Correlating Electrical Resistance Change With Mechanical Damage In Woven Sic/Sic Composites: Experiment And Modeling, Thanyawalai Sujidkul, Craig Smith, Zhijun Ma, Gregory Morscher, Zhenhai Xia
Correlating Electrical Resistance Change With Mechanical Damage In Woven Sic/Sic Composites: Experiment And Modeling, Thanyawalai Sujidkul, Craig Smith, Zhijun Ma, Gregory Morscher, Zhenhai Xia
Dr. Gregory N. Morscher
Silicon carbide (SiC) fiber-reinforced SiC matrix composites are inherently multifunctional materials. In addition to their primary function as a structural material, the electric properties of the SiC/SiC composites could be used for the sensing and monitoring of in situ damage nucleation and evolution. To detect damage and use that information to further predict the useful life of a particular component, it is necessary to establish the relationship between damage and electrical resistance change. Here, two typical SiC/SiC composites, melt infiltrated (MI), and chemical vapor infiltrated (CVI) woven SiC/SiC composites, were tested to establish the relationship between the electrical response and …
Monitoring Interlaminar Crack Growth In Ceramic Matrix Composites Using Electrical Resistance, Rabih Mansour, Emmanuel Maillet, Gregory Morscher
Monitoring Interlaminar Crack Growth In Ceramic Matrix Composites Using Electrical Resistance, Rabih Mansour, Emmanuel Maillet, Gregory Morscher
Dr. Gregory N. Morscher
This letter introduces a method that uses electrical resistance to monitor crack growth during interlaminar fracture testing of woven SiC fiber-reinforced SiC matrix composites at room temperature without visual observation. The estimated crack length is in excellent agreement with the measured length after subtracting a constant value of resistance related to the initial stage of crack development. This non-visual monitoring method holds great promise for in situ measurement of crack growth during high-temperature testing of ceramic matrix composites.