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- Biomedical materials (1)
- Corrosion (1)
- Creep (1)
- Design of experiments (DOE) (1)
- Diagonal crack (1)
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- Digital design (1)
- Extreme vertices mixture design (EVMD) (1)
- Finishing (1)
- Gait analysis; Inertial sensors; Motion capturing; Optimal control (1)
- Hybrid modeling (1)
- Inclined bar (1)
- Metals and alloys (1)
- Mg nanocomposite (1)
- Mg-Li-Al alloy (1)
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- NiTi (1)
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- Surface engineering (1)
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- Variable-stiffness actuators; human-assist devices; flexible beams; energy-efficient actuators (1)
Articles 1 - 9 of 9
Full-Text Articles in Entire DC Network
Estimation Of Gait Kinematics And Kinetics From Inertial Sensor Data Using Optimal Control Of Musculoskeletal Models, Eva Dorschky, Marlies Nitschke, Ann-Kristin Seifer, Antonie J. Van Den Bogert, Bjoern M. Eskofier
Estimation Of Gait Kinematics And Kinetics From Inertial Sensor Data Using Optimal Control Of Musculoskeletal Models, Eva Dorschky, Marlies Nitschke, Ann-Kristin Seifer, Antonie J. Van Den Bogert, Bjoern M. Eskofier
Mechanical Engineering Faculty Publications
Inertial sensing enables field studies of human movement and ambulant assessment of patients. However, the challenge is to obtain a comprehensive analysis from low-quality data and sparse measurements. In this paper, we present a method to estimate gait kinematics and kinetics directly from raw inertial sensor data performing a single dynamic optimization. We formulated an optimal control problem to track accelerometer and gyroscope data with a planar musculoskeletal model. In addition, we minimized muscular effort to ensure a unique solution and to prevent the model from tracking noisy measurements too closely. For evaluation, we recorded data of ten subjects walking …
Statistical Optimization Of Stress Level In Mg-Li-Al Alloys Upon Hot Compression Testing, Rezawana Islam, Meysem Haghshenas
Statistical Optimization Of Stress Level In Mg-Li-Al Alloys Upon Hot Compression Testing, Rezawana Islam, Meysem Haghshenas
Mechanical Engineering Faculty Publications
In the present study, a response optimization method using Extreme Vertices Mixer Design (EVMD) approach is proposed for stress optimization in a thermomechanically processed Mg-Li-Al alloy. Experimentation was planned as per mixed design proportions of Mg, Li and Al and process variables (i.e. temperature and strain rate). Each experiment has been performed under different conditions of factors proportions and process variables. The response, particularly stress has been considered for each experiment. The response is optimized to find an optimum condition when the contributing factors influence material characteristics in such a way, to achieve better strength, ductility and corrosion resistance. Estimated …
Magnesium Nanocomposites: An Overview On Time-Dependent Plastic (Creep) Deformation, Meysem Haghshenas, Manoj Gupta
Magnesium Nanocomposites: An Overview On Time-Dependent Plastic (Creep) Deformation, Meysem Haghshenas, Manoj Gupta
Mechanical Engineering Faculty Publications
Magnesium (Mg) nanocomposites are created when nano-size particles are embedded into the Mg (or Mg alloy) matrix. The Mg nanocomposites, cited as high-strength energy-saving materials of future, are a group of emerging materials with excellent combination of strength and ductility and superior specific strength property (strength-to-weight ratio). Having said this, Mg nanocomposites are considered as promising replacement for other structural alloys (i.e. aluminum and titanium) wherever low density and high strength are required, i.e. transportation, aerospace, defense, etc. To be able to apply this group of materials for real components, different failure mechanisms at ambient and elevated temperatures under …
Limit Equilibrium Method-Based Shear Strength Prediction For Corroded Reinforced Concrete Beam With Inclined Bars, Yafei Ma, Baoyong Lu, Zhongzhao Guo, Lei Wang, Hailong Chen, Jianren Zhang
Limit Equilibrium Method-Based Shear Strength Prediction For Corroded Reinforced Concrete Beam With Inclined Bars, Yafei Ma, Baoyong Lu, Zhongzhao Guo, Lei Wang, Hailong Chen, Jianren Zhang
Mechanical Engineering Faculty Publications
Shear strength is a widely investigated parameter for reinforced concrete structures. The corrosion of reinforcement results in shear strength reduction. Corrosion has become one of the main deterioration factors in reinforced concrete beam. This paper proposes a shear strength model for beams with inclined bars based on a limit equilibrium method. The proposed model can be applied to both corroded and uncorroded reinforced concrete beams. Besides the tensile strength of longitudinal steel bars, the shear capacity provided by the concrete on the top of the diagonal crack, the tensile force of the shear steel at the diagonal crack, the degradation …
Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter
Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter
Mechanical Engineering Faculty Publications
Actuators intended for human–machine interaction systems are usually designed to be mechanically compliant. Conventional actuators are not suitable for this purpose due to typically high stiffness. Advanced powered prosthetic and orthotic devices can vary their stiffness during a motion cycle and are power-efficient. This paper proposes a novel actuator design that modulates stiffness by means of a flexible beam. A motorized drive system varies the active length of the cantilever beam, thus achieving stiffness modulation. New large deflection formulation for cantilever beams with rolling contact constraints is used to determine the moment produced by the actuator. To validate the proposed …
Achieving Superelasticity In Additively Manufactured Niti In Compression Without Post-Process Heat Treatment, Narges Shayesteh Moghaddam, Soheil Saedi, Amirhesam Amerinatanzi, Alejandro Hinojos, Ali Ramazani, Julia Kundin, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia
Achieving Superelasticity In Additively Manufactured Niti In Compression Without Post-Process Heat Treatment, Narges Shayesteh Moghaddam, Soheil Saedi, Amirhesam Amerinatanzi, Alejandro Hinojos, Ali Ramazani, Julia Kundin, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia
Mechanical Engineering Faculty Publications
Shape memory alloys (SMAs), such as Nitinol (i.e., NiTi), are of great importance in biomedical and engineering applications due to their unique superelasticity and shape memory properties. In recent years, additive manufacturing (AM) processes have been used to produce complex NiTi components, which provide the ability to tailor microstructure and thus the critical properties of the alloys, such as the superelastic behavior and transformation temperatures (TTs), by selection of processing parameters. In biomedical applications, superelasticity in implants play a critical role since it gives the implants bone-like behavior. In this study, a methodology of improving superelasticity in Ni-rich NiTi components …
Computationally Efficient, Multi-Domain Hybrid Modeling Of Surface Integrity In Machining And Related Thermomechanical Finishing Processes, Julius M. Schoop, David Adeniji, Ian S. Brown
Computationally Efficient, Multi-Domain Hybrid Modeling Of Surface Integrity In Machining And Related Thermomechanical Finishing Processes, Julius M. Schoop, David Adeniji, Ian S. Brown
Mechanical Engineering Faculty Publications
In order to enable more widespread implementation of sophisticated process modeling, a novel, rapidly deployable multi-physics hybrid model of surface integrity in finishing operations is proposed. Rather than modeling detailed chip formation mechanics, as is common in numerical models, the proposed models integrates existing analytical and semi-empirical models of the plastic, elastic, thermal and thermodynamic domains. Using this approach, highly complex surface integrity phenomena such as residual stresses, grain size, phase composition, microhardness profile, etc. can be accurately predicted in a manner of seconds. It is envisioned that this highly efficient modeling scheme will drive new innovations in surface engineering.
Analysis Of Human Behavior For Robot Design And Control, Tyagi Ramakrishnan, Seok Hun Kim, Kyle B. Reed
Analysis Of Human Behavior For Robot Design And Control, Tyagi Ramakrishnan, Seok Hun Kim, Kyle B. Reed
Mechanical Engineering Faculty Publications
The combined gait asymmetry metric (CGAM) provides a method to synthesize human gait motion. The metric is weighted to balance each parameter’s effect by normalizing the data so all parameters are more equally weighted. It is designed to combine spatial, temporal, kinematic, and kinetic gait parameter asymmetries. It can also combine subsets of the different gait parameters to provide a more thorough analysis. The single number quantifying gait could assist robotic rehabilitation methods to optimize the resulting gait patterns. CGAM will help define quantitative thresholds for achievable balanced overall gait asymmetry. The study presented here compares the combined gait parameters …
Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert
Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
This paper compares predictions of metabolic energy expenditure in gait using seven metabolic energy expenditure models to assess their correlation with experimental data. Ground reaction forces, marker data, and pulmonary gas exchange data were recorded for six walking trials at combinations of two speeds, 0.8 m/s and 1.3 m/s, and three inclines, -8% (downhill), level, and 8% (uphill). The metabolic cost, calculated with the metabolic energy models was compared to the metabolic cost from the pulmonary gas exchange rates. A repeated measures correlation showed that all models correlated well with experimental data, with correlations of at least 0.9. The model …