Fatigue and Fracture Research Lab

• Metal Fatigue • Fracture Mechanics • Additive Manufacturing • Multiaxial Fatigue • Failure Analysis • Materials Mechanical Behavior

• Fatigue of  Polymers • Biomedical Implant Design • Mechanical Behavior of Bone • Composite Materials • Damage Mechanics • Mechanical Design • Experimental Mechanics

Lab Director: Mohammad Amjadi, Ph.D. Assistant Professor of Mechanical Engineering   Arkansas Tech University  1811 North Boulder Ave.   Corley 222  Russellville, AR 72801  Phone: 479-964-0583, Ext. 4204 Email: mamjadi@atu.edu  Google Scholar    LinkedIn
Minh Tran: Minh Tran is a Mechanical Engineering graduate student doing research on fatigue behavior of porous titanium and thermoplastic cellular structures. Minh's research aims to enhance the performance and durability of materials used in advanced engineering applications. In addition to his academic work, Minh gained valuable industry experience during a summer internship at AESC US headquarters in Smyrna, Tennessee. As an electric vehicle (EV) and energy storage systems (ESS) battery cell process engineer intern, Minh developed an automated packaging machine capable of processing 15 battery cells per minute, improving efficiency and safety.
Brayden May: Brayden May is an undergraduate researcher, majoring in Mechanical Engineering. His research focuses on the fatigue behavior of 3D-printed thermoplastics, contributing to advancements in additive manufacturing techniques and material durability testing.
Genya Ohama: A Bachelor's student majoring in Mechanical Engineering at Arkansas Tech University, conducted fatigue testing experiments on 17-4 Stainless Steel material produced by binder jetting.

 

MONOTONIC TESION TESTING
Basic mechanical properties of materials can be obtained using a simple monotonic tension test. Properties such as elastic modulus, yield strength, ultimate strength, fracture stress, ductility, and elongation at break.

FATIGUE TESTING
Fatigue Testing measures the ability of samples to withstand the application of repeated load cycles to determine their stress limit with the corresponding life.

FRACTURE TOUGHNESS TESTING
Fracture Toughness Testing provides information about a material’s resistance to crack extension under a steadily increasing load.

FATIGUIE CRACK GROWTH TESTING
Crack growth testing involves subjecting materials to cyclic loading conditions to analyze the propagation rate of cracks, providing critical data for assessing the fatigue resistance and durability of the material.

HARDNESS TEST
Perform indentation on the sample, creating permanent deformation, to evaluate the material’s strength, ductility, and wear                resistance.

FRACTOGRAPHY
Evaluate the fracture surface of the sample to determine the cause and analyze the failure in the engineering structure.

FRACTURE TOUGHNESS TESTING
Also known as the stress-relaxation test. Supply a constant load at a constant temperature over a period of time to determine the strength and heat resistance of a sample’s material.

1. FATIGUE TESTING SYSTEM 
    EHF-E SERVOPULSER, 50KN, ± 50 mm from Shimadzu

    Features include:

• Up to ±50 kN axial force capacity
• GRIP SET, SPLIT FLANGE, 50KN
• Crack growth and fracture toughness grip set and sensor
• Wide range of grips, fixtures, and accessories

2. ROTATING BENDING 
3. OPTICAL MICROSCOPE  
4. HARDNESS TESTER 
5. INFRARED CAMERA

 

 

Auburn University University of Arkansas for Medical Sciences, Biomechanics lab

• Amjadi, M.; Fatemi, A.,” A critical plane approach for multiaxial fatigue life prediction of short fiber reinforced thermoplastic composites”. Composites Part A: Applied Science and Manufacturing, 2024. 180: p. 108050.
• Amjadi, M.; Fatemi, A.,” A Fatigue Damage Model for Life Prediction of Injection Molded Short Fiber Reinforced Thermoplastic Composites”. Polymers. 2021, 13, 2250. 
• Amjadi, M.; Fatemi, A.,”Tensile Behavior of High-Density Polyethylene Including the Effects of Processing Technique, Thickness, Temperature, and Strain Rate”. Polymers 2020, 12, 1857. 
• Amjadi, M.; Fatemi, A.,” Creep and fatigue behaviors of High-Density Polyethylene (HDPE): Effects of temperature, mean stress, frequency, and processing technique”. International Journal of Fatigue. 2020; 141: 105871. doi: 10.1016/j.ijfatigue.2020.105871.
• Amjadi, M.; Fatemi, A. Creep behavior and modeling of high-density polyethylene (HDPE). Polymer Testing 2021, 94, 107031, doi: 10.1016/j.polymertesting.2020.107031.
• Amjadi, M.; Fatemi, A.,” Multiaxial Fatigue Behavior of Thermoplastics Including Mean Stress and Notch Effects: Experiments and Modeling”. International Journal of Fatigue. 2020; 136: 105571. doi: 10.1016/j.ijfatigue.2020.105571.
• Amjadi, M.; Fatemi, A.,” Multiaxial Fatigue Behavior of High-Density Polyethylene (HDPE) Including Notch Effect: Experiments and Modeling”. ICMFF12 - 12th International Conference on Multiaxial Fatigue and Fracture; MATEC Web of Conferences. 2019; 300: 05001. doi: 10.1051/matecconf/201930005001.
• Amjadi M, Nikkhoo M, Khalaf K, et al., “An in silico parametric model of vertebrae trabecular bone based on density and microstructural parameters to assess risk of fracture in osteoporosis”. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine. 2014;228(12):1281-1295. doi:10.1177/0954411914563363.

• www.efatigue.com

 

Mohammad Amjadi, Ph.D. Assistant Professor of Mechanical Engineering   Arkansas Tech University  1811 North Boulder Ave.   Corley 222  Russellville, AR 72801  Phone: 479-964-0583, Ext. 4204 Email: mamjadi@atu.edu