Author: Eray Gunel
Publisher:
ISBN:
Category :
Languages : en
Pages : 537
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Book Description
The main aim of this study is to investigate stress whitening and associated micro-deformation mechanism in thermoformed particle filled acrylic sheets. For stress whitening quantification, a new index was developed based on image histograms in logarithmic scale of gray level. Stress whitening levels in thermoformed acrylic composites was observed to increase with increasing deformation limit, decreasing forming rate and increasing forming temperatures below glass transition. Decrease in stress whitening levels above glass transition with increasing forming temperature was attributed to change in micro-deformation behavior. Surface deformation feature investigated with scanning electron microscopy showed that source of stress whitening in thermoformed samples was a combination of particle failure and particle disintegration depending on forming rate and temperature. Stress whitening level was strongly correlated to intensity of micro-deformation features.^On the other hand, thermoformed neat acrylics displayed no surface discoloration which was attributed to absence of micro-void formation on the surface of neat acrylics. Experimental damage measures (degradation in initial, secant, unloading modulus and strain energy density) have been inadequate in describing damage evolution in successive thermoforming applications on the same sample at different levels of deformation. An improved version of dual-mechanism viscoplastic material model was proposed to predict thermomechanical behavior of neat acrylics under non-isothermal conditions. Simulation results and experimental results were in good agreement and failure of neat acrylics under non-isothermal conditions ar low forming temperatures were succesfully predicted based on entropic damage model. Particle and interphase failure observed in acrylic composites was studied in a multi-particle unit cell model with different volume fractions.^Damage evolution due to particle failure and interphase failure was simulated by implementing imperfect interphase within particle agglomerates and imperfect interphase between filler and matrix through a user defined interphase model. In parametric studies, influence of interphase strength, interphase stiffness and interparticle distance was studied to determine conditions that will favor particle and/or interphase failure between matrix and filler. Composite elastic modulus results from finite element analysis results of unit cell models were in good agreement with experimental results and analytical model predictions at different temperatures for various volume fractions of fillers. A temperature dependent strength criterion for initiation of particle failure in acrylic composites was determined based on comparison of finite element analysis results of unit cell model with expereimental results for acrylic composites.
Author: Cemal Basaran
Publisher: Springer Nature
ISBN: 3031186214
Category : Science
Languages : en
Pages : 531
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Book Description
This second edition adds new sections on derivation of dynamic equilibrium equations in unified mechanics theory and solution of an example, derivation of very high cycle fatigue thermodynamic fundamental equation and application/verification with two metal fatigue examples, derivation of thermodynamic fundamental equations for metal corrosion, examples of corrosion – fatigue interaction. There is also an example of ultrasonic vibration fatigue and one traditional tension/compression loading in elastic regime. While updated and augmented throughout, the book retains its description of the mathematical formulation and proof of the unified mechanics theory (UMT), which is based on the unification of Newton’s laws and the laws of thermodynamics. It also presents formulations and experimental verifications of the theory for thermal, mechanical, electrical, corrosion, chemical and fatigue loads, and it discusses why the original universal laws of motion proposed by Isaac Newton in 1687 are incomplete. The author provides concrete examples, such as how Newton’s second law, F = ma, gives the initial acceleration of a soccer ball kicked by a player, but does not tell us how and when the ball would come to a stop. Over the course of the text, Dr. Basaran illustrates that Newtonian mechanics does not account for the thermodynamic changes happening in a system over its usable lifetime. And in this context, this book explains how to design a system to perform its intended functions safely over its usable life time and predicts the expected lifetime of the system without using empirical models, a process currently done using Newtonian mechanics and empirical degradation/failure/fatigue models which are curve-fit to test data. Written as a textbook suitable for upper-level undergraduate mechanics courses, as well as first year graduate level courses, this book is the result of over 25 years of scientific activity with the contribution of dozens of scientists from around the world.
Author:
Publisher:
ISBN:
Category : Ceramic materials
Languages : en
Pages : 496
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Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2540
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Author: I. M. Ward
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 504
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Book Description
A concise, self-contained introduction to solid polymers, the mechanics of their behavior and molecular and structural interpretations. This updated edition provides extended coverage of recent developments in rubber elasticity, relaxation transitions, non-linear viscoelastic behavior, anisotropic mechanical behavior, yield behavior of polymers, breaking phenomena, and other fields.
Author: C. Keith Riew
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 408
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Book Description
Discusses new developments in the theoretical and practical approaches of toughness in thermosets and thermoplastics. Covers review and reports of world-recognized scientists on the latest advances in toughening science and technology. Provides a review of the principles of toughening and discusses synthetic approaches to the modification of plastics for scientists and engineers. Examines the applications of fracture mechanics and failure mechanisms in order to better understand and improve toughening. Details the effects of microstructure, morphology, and mechanical properties on performance of plastics.
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 390
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Book Description
Author: Michel Cloitre
Publisher: Springer Science & Business Media
ISBN: 3642163815
Category : Technology & Engineering
Languages : en
Pages : 260
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Book Description
From Polymers to Colloids: Engineering the Dynamic Properties of Hairy Particles, by D. Vlassopoulos and G. Fytas * Nonlinear Rheological Properties of Dense Colloidal Dispersions Close to a Glass Transition Under Steady Shear, by M. Fuchs * Micromechanics of Soft Particle Glasses, by R. T. Bonnecaze and M. Cloitre * Quantitative Imaging of Concentrated Suspensions Under Flow, by L. Isa, R. Besseling, A. B. Schofield and W. C. K. Poon * Soft and Wet Materials: From Hydrogels to Biotissues, by J. P. Gong and Y. Osada
Author: Cemal Basaran
Publisher: Springer Nature
ISBN: 3030577724
Category : Science
Languages : en
Pages : 452
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Book Description
This text describes the mathematical formulation and proof of the unified mechanics theory (UMT) which is based on the unification of Newton’s laws and the laws of thermodynamics. It also presents formulations and experimental verifications of the theory for thermal, mechanical, electrical, corrosion, chemical and fatigue loads, and it discusses why the original universal laws of motion proposed by Isaac Newton in 1687 are incomplete. The author provides concrete examples, such as how Newton’s second law, F = ma, gives the initial acceleration of a soccer ball kicked by a player, but does not tell us how and when the ball would come to a stop. Over the course of Introduction to Unified Mechanics Theory, Dr. Basaran illustrates that Newtonian mechanics does not account for the thermodynamic changes happening in a system over its usable lifetime. And in this context, this book explains how to design a system to perform its intended functions safely over its usable life time and predicts the expected lifetime of the system without using empirical models, a process currently done using Newtonian mechanics and empirical degradation/failure/fatigue models which are curve-fit to test data. Written as a textbook suitable for upper-level undergraduate mechanics courses, as well as first year graduate level courses, this book is the result of over 25 years of scientific activity with the contribution of dozens of scientists from around the world including USA, Russia, Ukraine, Belarus, Spain, China, India and U.K.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 974
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Book Description
