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Articles 31 - 36 of 36

Full-Text Articles in Mechanical Engineering

Role Of Interphase In The Mechanical Behavior Of Silica/Epoxy Resin Nanocomposites, Yi Hua, Linxia Gu, Sundaralingam Premaraj, Xiaodong Zhang Jan 2015

Role Of Interphase In The Mechanical Behavior Of Silica/Epoxy Resin Nanocomposites, Yi Hua, Linxia Gu, Sundaralingam Premaraj, Xiaodong Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

A nanoscale representative volume element has been developed to investigate the effect of interphase geometry and property on the mechanical behavior of silica/epoxy resin nanocomposites. The role of interphase–matrix bonding was also examined. Results suggested that interphase modulus and interfacial bonding conditions had significant influence on the effective stiffness of nanocomposites, while its sensitivities with respect to both the thickness and the gradient property of the interphase was minimal. The stiffer interphase demonstrated a higher load-sharing capacity, which also increased the stress distribution uniformity within the resin nanocomposites. Under the condition of imperfect interfacial bonding, the effective stiffness of nanocomposites …


Towards Tuning The Mechanical Properties Of Three-Dimensional Collagen Scaffolds Using A Coupled Fiber-Matrix Model, Shengmao Lin, Lauren A. Hapach, Cynthia Reinhart-King, Linxia Gu Jan 2015

Towards Tuning The Mechanical Properties Of Three-Dimensional Collagen Scaffolds Using A Coupled Fiber-Matrix Model, Shengmao Lin, Lauren A. Hapach, Cynthia Reinhart-King, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Scaffold mechanical properties are essential in regulating the microenvironment of three-dimensional cell culture. A coupled fiber-matrix numerical model was developed in this work for predicting the mechanical response of collagen scaffolds subjected to various levels of non-enzymatic glycation and collagen concentrations. The scaffold was simulated by a Voronoi network embedded in a matrix. The computational model was validated using published experimental data. Results indicate that both non-enzymatic glycation-induced matrix stiffening and fiber network density, as regulated by collagen concentration, influence scaffold behavior. The heterogeneous stress patterns of the scaffold were induced by the interfacial mechanics between the collagen fiber network …


In Situ Longitudinal Pre-Stretch In The Human Femoropopliteal Artery, Alexey Kamenskiy, Andreas Seas, Grant Bowen, Paul Deegan, Anastasia Desyatova, Nick Bohlim, William Poulson, Jason N. Mactaggart Jan 2015

In Situ Longitudinal Pre-Stretch In The Human Femoropopliteal Artery, Alexey Kamenskiy, Andreas Seas, Grant Bowen, Paul Deegan, Anastasia Desyatova, Nick Bohlim, William Poulson, Jason N. Mactaggart

Department of Mechanical and Materials Engineering: Faculty Publications

In situ longitudinal (axial) pre-stretch (LPS) plays a fundamental role in the mechanics of the femoropopliteal artery (FPA). It conserves energy during pulsation and prevents buckling of the artery during limb movement. We investigated how LPS is affected by demographics and risk factors, and how these patient characteristics associate with the structural and physiologic features of the FPA. LPS was measured in n=148 fresh human FPAs (14–80 years old). Mechanical properties were characterized with biaxial extension and histopathological characteristics were quantified with Verhoeff-Van Gieson Staining. Constitutive modeling was used to calculate physiological stresses and stretches which were then analyzed …


Multiscale Modeling Of Skeletal Muscle Active Contraction In Relation To Mechanochemical Coupling Of Molecular Motors, Jiangcheng Chen, Xiaodong Zhang, Shengmao Lin, He Wang, Linxia Gu Jan 2015

Multiscale Modeling Of Skeletal Muscle Active Contraction In Relation To Mechanochemical Coupling Of Molecular Motors, Jiangcheng Chen, Xiaodong Zhang, Shengmao Lin, He Wang, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, a mathematical model was developed to relate the mechanochemical characterizations of molecular motors with the macroscopic manifestation of muscle contraction. Non-equilibrium statistical mechanics were used to study the collective behavior of myosin molecular motors in terms of the complex conformation change and multiple chemical states in one working cycle. The stochastic evolution of molecular motor probability density distribution during the contraction of sarcomere was characterized by the Fokker-Planck Equation. Quick muscle contraction was demonstrated by the collective dynamic behavior of myosin motors, the muscle contraction force, and the muscle contraction velocity-force relation. Our results are validated against …


Color And Texture Morphing With Colloids On Multilayered Surfaces, Ziguang Chen, Shumin Li, Andrew Arkebauer, George Gogos, Li Tan Jan 2015

Color And Texture Morphing With Colloids On Multilayered Surfaces, Ziguang Chen, Shumin Li, Andrew Arkebauer, George Gogos, Li Tan

Department of Mechanical and Materials Engineering: Faculty Publications

Dynamic morphing of marine species to match with environment changes in color and texture is an advanced means for surviving, self-defense, and reproduction. Here we use colloids that are placed inside a multilayered structure to demonstrate color and texture morphing. The multilayer is composed of a thermal insulating base layer, a light absorbing mid layer, and a liquid top layer. When external light of moderate intensity (∼0.2 W cm−2) strikes the structure, colloids inside the liquid layer will be assembled to locations with an optimal absorption. When this system is exposed to continuous laser pulses, more than 18 000 times …


Self‑Propelled Droplets On Heated Surfaces With Angled Self‑Assembled Micro/Nanostructures, Cory Kruse, Isra Somanas, Troy Anderson, Chris Wilson, Craig Zuhlke, Dennis Alexander, George Gogos, Sidy Ndao Jan 2015

Self‑Propelled Droplets On Heated Surfaces With Angled Self‑Assembled Micro/Nanostructures, Cory Kruse, Isra Somanas, Troy Anderson, Chris Wilson, Craig Zuhlke, Dennis Alexander, George Gogos, Sidy Ndao

Department of Mechanical and Materials Engineering: Faculty Publications

Directional and ratchet-like functionalized surfaces can induce liquid transport without the use of an external force. In this paper, we investigate the motion of liquid droplets near the Leidenfrost temperature on functionalized self-assembled asymmetric microstructured surfaces. The surfaces, which have angled microstructures, display unidirectional properties. The surfaces are fabricated on stainless steel through the use of a femtosecond laser-assisted process. Through this process, mound-like microstructures are formed through a combination of material ablation, fluid flow, and material redeposition. In order to achieve the asymmetry of the microstructures, the femtosecond laser is directed at an angle with respect to the sample …