Search results for "T method"
showing 10 items of 1254 documents
On the finite element approximation for maxwell’s problem in polynomial domains of the plane
1981
The time-harmonic Maxwell boundary value problem in polygonal domains of R2 is considered. The behaviour of the solution in the neighbourhood of nonregular boundary points is given and asymptotic error estimates in L2- and in curl-div-norm for a finite element approximation of the solution are derived
Hygrothermal effect on moisture kinetics and mechanical properties of hemp/polypropylene composite: Experimental and numerical studies
2015
The exposition of thermoplastic composites reinforced with natural fibers to moisture and heat is likely to lower their mechanical properties and restrain their use in the design of parts. The present work is focussed on investigating the effects of hygrothermal aging on the mechanical behaviour of injected polypropylene reinforced with short hemp fibers. Moreover, the kinetic of isothermal moisture absorption has been studied for four immersion temperatures. The experimental results show that the time taken to reach saturation decreases significantly with increase in immersion temperature. These tests also reveal that moisture absorption in this type of materials does not follow Fick's law…
FEM Simulation of Laminated Lightweight Materials Processed through Single Point Incremental Forming
2015
The aim of present paper is to realize the FEM simulation of laminated lightweight material processed through single point incremental forming. Thus a laminated material, aluminum - polypropylene - aluminum (Al-PP-Al), as sheet 1.2 mm thickness was used. For these material the hardening curve was determinate. These values were used to describe elastic-plastic behavior of the material during single point incremental forming process simulation. Single point incremental forming process simulation aimed to assess the distribution of values and maximum and minimum strains, the material thickness of the specimen and the technological force for the two strategies for obtaining the truncated cone s…
Modeling elastic properties of short flax fiber-reinforced composites by orientation averaging
2010
Abstract Natural fibers of plant origin, used as reinforcement in polymer matrix composite materials, exhibit highly anisotropic elastic properties due to their complex internal structure. Mechanical properties can be evaluated not only by tests but also by mechanical models reflecting the principal morphological features of fibers. Such a FEM model is applied to estimate the elastic properties of a unit cell of a short-fiber-reinforced composite, an elementary flax fiber embedded in a polymer matrix. Orientation averaging approach is used for prediction of the stiffness of short flax fiber reinforced polymer matrix composite. The numerical estimates of Young’s modulus are compared to the t…
Analytical and numerical comparison of position based methods versus physics based formulation of mechanical systems
2017
La simulación de sistemas mecanicos para videojuegos y otras aplicaciones interactivas impone restricciones importantes como estabilidad, flexibilidad en las escenas, y complejidad computacional. En los últimos años han aparecido múltiples estrategias de resolución para sistemas mecánicos con restricciones. Algunos de los más populares en el ámbito de videojuegos únicamente usan las posiciones de las partículas y un algoritmo de proyección sobre la variedad definida por las restricciones, evitando la manipulación de la primera derivada del sistema (las velocidades), obteniendo así gran estabilidad numérica. El principal problema de estos métodos es la dependencia en parámetros no físicos, d…
Singularity formation and separation phenomena in boundary layer theory
2009
In this paper we review some results concerning the behaviour of the incompressible Navier–Stokes solutions in the zero viscosity limit. Most of the emphasis is put on the phenomena occurring in the boundary layer created when the no-slip condition is imposed. Numerical simulations are used to explore the limits of the theory. We also consider the case of 2D vortex layers, i.e. flows with internal layers in the form of a rapid variation, across a curve, of the tangential velocity.
Study of new joining technique: flat clinching
2007
In this paper a development of clinching, called flat clinching, is presented. After a press clinching process, the joined sheets have been deformed by a punch with a lower diameter against a flat die. In this way a new configuration is created with a geometry that has no discontinuity on the external surface (bottom). A new procedure has also been tested: the second step is perfomed by pressing the joint between two flat dies. This second case has revealed itself to be very effective.Tensile tests have been done to compare the joints strength among the various joining techniques. Moreover some joints have been cut to analyse the changing of the contact line shape and how its characteristic…
Comparison of the environmental assessment of an identical office building with national methods
2019
The IEA EBC Annex 72 focuses on the assessment of the primary energy demand, greenhouse gas emissions and environmental impacts of buildings during production, construction, use (including repair and replacement) and end of life (dismantling), i.e. during the entire life cycle of buildings. In one of its activities, reference buildings (size, materialisation, operational energy demand, etc.) were defined on which the existing national assessment methods are applied using national (if available) databases and (national/regional) approaches. The ?be2226? office building in Lustenau, Austria was selected as one of the reference buildings. TU Graz established a BIM model and quantified the amou…
Investigating the causal mechanisms underlying the customization of software development methods
2017
Over the last four decades, software development has been one of the mainstream topics in the Software Engineering and Information Systems disciplines. Thousands of methods have been put forward offering prescriptions for software development processes. The goal of these methods is to produce high-quality software in a systematic manner. However, it is widely known that these methods are rarely followed as prescribed – developers often modify or skip different steps, practices, or quality rules recommended by software development methods. While a group of previous studies suggests that maximizing the flexibility and leanness of software development processes is the key driver of such custom…
Influence of substrate design for in vitro mechanical testing
2019
Background: The goal of this study was to evaluate the influence of dental substrate simulator material, and the presence of root and periodontal ligament on the stress distribution in an adhesively-cemented monolithic crown.Material and methods: Five (5) 3D models according to the substrate simulator material and shape were modeled with CAD software for conducting non-linear finite element analysis (FEA): Tooth with and without periodontal ligament - subgroup "pl" (groups Tooth+pl and Tooth-pl), machined tooth in epoxy-resin with and without pulp chamber - subgroup "pc" (ER+pc and ER-pc) and simplified epoxy-resin substrate without pulp chamber and roots (SiER). Next, adhesively-cemented m…