scholarly journals A Numerical Study on Spring Rate of Composite Leaf Spring from Material Parameters

2014 ◽  
Vol 16 (2) ◽  
pp. 1279-1284 ◽  
Author(s):  
오성하 ◽  
Boklok Choi
Keyword(s):  
Numerical Study ◽  
Leaf Spring ◽  
Spring Rate ◽  
Material Parameters

Kombinierte experimentelle und numerische Studie zur schwindinduzierten Rissbildung zementgebundener Werkstoffe / Combined Experimental and Numerical Study to assess Shrinkage Cracking of Cement-Based Materials

1998 ◽  
Vol 4 (5) ◽  
pp. 479-506 ◽  
Author(s):  
G. Martinola ◽  
H. Sadouki
Keyword(s):  
Numerical Study ◽  
Decisive Role ◽  
Shrinkage Cracking ◽  
Nonlinear Fracture Mechanics ◽  
Material Parameters ◽  
Nonlinear Fracture ◽  
Cement Based Materials ◽  
Different Types ◽  
Experimental Findings ◽  
Relevant Material

Abstract In this contribution, a combined experimental and numerical study to assess the cracking resistance of cement-based materials subjected to desiccation is outlined. Experimentally, the tendency to hygral cracking is determined by means of mortar ring specimens exposed to drying atmosphere. A numerical model based on the nonlinear theory of diffusion and nonlinear fracture mechanics is developed. The relevant hygral and mechanical parameters and laws needed for the model have been determined by means of adequate experiments analyzed by inverse analyses. The hygro-mechanical behaviour of two different types of mortar is studied. Numerical results have been compared to experimental findings. Furthermore, a parametric study has been carried out with the aim to characterize the relevant material parameters influencing shrinkage cracking. It can be concluded that a combination of experimental and numerical methods can play a decisive role in optimizing mortars or concretes with respect to predefined and required material properties. In this way, the durability of concrete structures can be significantly enhanced.

The Numerical Study for the Thermal Characteristics of 3D Vertical Stacked Die Packages

2009 ◽  
Author(s):  
Chih-Kuang Yu ◽  
Ming-Che Hsieh ◽  
Chun-Kai Liu ◽  
Ming-Ji Dai ◽  
Ra-Min Tain
Keyword(s):  
Numerical Study ◽  
Thermal Characteristics ◽  
Junction Temperature ◽  
Geometrical Parameters ◽  
Heat Transfer Mechanism ◽  
3 Dimensional ◽  
Material Parameters ◽  
Silicon Vias ◽  
Thermal Simulations ◽  
Volume Method

In this study, the thermal simulations of 3 dimensional IC packages base on 4-layer vertical stacked die (bare die on bare die) with TSV (through silicon vias) and micro-bumps structure are conducted. The thermal models by finite volume method are developed for different geometrical parameters (TSV, micro-bumps distribution arrangement and spacer thickness) and material property (thermal conductivity of spacer). The thermal performance and the heat transfer mechanism for the stacked die package are analyzed for optimizing the geometrical and material parameters. Not only the temperature distributions but also the junction temperature and thermal resistances in 4-layer stacked die package with different multi-die power configurations are shown and discussed.

Stochastic Fracture Simulations of Concrete Beams with Shallow Notches

2013 ◽  
Vol 592-593 ◽  
pp. 229-232
Author(s):  
Jan Eliáš ◽  
Miroslav Vořechovský
Keyword(s):  
Mechanical Model ◽  
Concrete Beams ◽  
Numerical Study ◽  
Material Behavior ◽  
Concrete Fracture ◽  
Three Point Bending ◽  
Material Parameters ◽  
Fluctuation Rate ◽  
Level Model ◽  
Spatial Randomness

We present a numerical study on virtual concrete beams with shallow midspan notches loaded in three-point bending. We document how spatial randomness of material parameters allows a crack to initiate outside the shallow notch. The interacting effects of notch depth and fluctuation rate of material parameters are shown. We use a discrete meso-level model to simulate material behavior. An approach that introduces material spatial randomness into the discrete mechanical model for concrete fracture through an autocorrelated random field is briefly presented.

scholarly journals Peristaltic transport of viscoelastic bio-fluids with fractional derivative models

BIOMATH ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 1605161 ◽  
Author(s):  
Emilia Bazhlekova ◽  
Ivan Bazhlekov
Keyword(s):  
Reynolds Number ◽  
Fractional Derivative ◽  
Pressure Gradient ◽  
Numerical Study ◽  
Peristaltic Flow ◽  
Viscoelastic Flows ◽  
Long Wavelength ◽  
Material Parameters ◽  
Uniform Channel ◽  
Appl Math

Peristaltic flow of viscoelastic fluid through a uniform channel is considered under the assumptions of long wavelength and low Reynolds number. The fractional Oldroyd-B constitutive viscoelastic law is employed. Based on models for peristaltic viscoelastic flows given in a series of papers by Tripathi et al. (e.g. Appl Math Comput. 215 (2010) 3645–3654; Math Biosci. 233 (2011) 90–97) we present a detailed analytical and numerical study of the evolution in time of the pressure gradient across one wavelength. An analytical expression for the pressure gradient is obtained in terms of Mittag-Leffler functions and its behavior is analyzed. For numerical computation the fractional Adams method is used. The influence of the different material parameters is discussed, as well as constraints on the parameters under which the model is physically meaningful.

Numerical study of some post-cracking material parameters affecting nonlinear solutions in RC deep beams

1987 ◽  
Vol 14 (5) ◽  
pp. 655-666 ◽  
Author(s):  
A. A. Al-Manaseer ◽  
D. V. Phillips
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Deep Beam ◽  
Deep Beams ◽  
Interface Shear ◽  
Element Analysis ◽  
Tension Stiffening ◽  
Shear Transfer ◽  
Material Parameters ◽  
Nonlinear Solution

This paper describes a numerical study of some of the quasi-material parameters which are used to define the post-cracking response in smeared crack models for the nonlinear finite element analysis of reinforced concrete. The two major effects studied were interface shear transfer and tension stiffening. The investigation was carried out on a solid deep beam using a nonlinear plane stress formulation. Parabolic isoparametric elements were used with a standard nonlinear solution procedure.The effect of the quasi-material parameters was found to be significant in predicting the behaviour of the deep beam. A sudden drop in the stress at the cracking load was found to be important in the tension stiffening model. Different values can lead to different solutions for load–deflection curves, ultimate loads, and crack patterns. Also it was found that a large reduction in shear modulus to account for interface shear transfer can affect the nonlinear solution and cause numerical problems when used with a gradual release tension stiffening model with no discontinuity at the cracking load. Key words: deep beams, finite element, load deflection, post-cracking, shear transfer, tension stiffening, ultimate load.

An Approach for the Systematic Development of Progressive Light Weight Spring Element Concepts in Vehicle Constructions

2017 ◽  
Vol 742 ◽  
pp. 745-752
Author(s):  
Michael Knorre ◽  
Robert Brandt
Keyword(s):  
Systematic Approach ◽  
High Strength ◽  
Leaf Spring ◽  
Light Weight ◽  
Commercial Vehicles ◽  
Spring Rate ◽  
Single Leaf ◽  
Spring Element ◽  
Wide Range ◽  
Systematic Development

Commercial vehicles are mostly equipped with pneumatic spring elements which lead to a perfect height levelling and spring rate adjustment under different loading conditions. However, pneumatic springs are not common in light commercial vehicles where passive spring elements, e.g. single- and multi-leaf springs, are still be used. Since those vehicles are covering a wide range of different loads the spring elements frequently exhibit a progressive spring characteristic, i.e. the spring rate is adjusted under deflection as soon as the load is increased. The need for light weight design also relates to light commercial vehicle so that glass fibre reinforced plastic (GFRP) has become a suitable substitute for high strength steel. Furthermore GFRP allows for innovative as well as functionally and technologically improved constructional solutions of progressive spring elements, e.g. the single-leaf spring approach by Schürmann et al [1].However, the above mentioned solution is sometimes rather solitaire and no systematic approach for its genesis exits. Hence, this contribution shows an approach for a more systematic development of progressive light weight spring element concepts in vehicle construction. Different approaches of implementing a progressive spring rate characteristic are presented in the introduction. A simple analytical model of a bending beam considering a variety of boundary conditions has been set up to discuss the effect of bearing stiffness on the spring rate.The model serves as a basis for a kind of toolbox for a more systematic approach for the development of the desired progressive spring elements. It allows to identify and to select a balanced concept for a progressive light weight spring element which also considers the application of the appropriate spring material at any specific part of the construction.

scholarly journals Numerical Study of Concrete Mesostructure Effect on Lamb Wave Propagation

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2570 ◽  
Author(s):  
Beata Zima ◽  
Rafał Kędra
Keyword(s):  
Particle Size ◽  
Wave Propagation ◽  
Lamb Wave ◽  
Lamb Waves ◽  
Numerical Study ◽  
Diagnostic Methods ◽  
Material Parameters ◽  
The Difference ◽  
Dispersion Solution ◽  
Lamb Wave Propagation

The article presents the results of the numerical investigation of Lamb wave propagation in concrete plates while taking into account the complex concrete mesostructure. Several concrete models with randomly distributed aggregates were generated with the use of the Monte Carlo method. The influence of aggregate ratio and particle size on dispersion curves representing Lamb wave modes was analyzed. The results obtained for heterogeneous concrete models were compared with theoretical results for homogeneous concrete characterized by the averaged macroscopic material parameters. The analysis indicated that not only do the averaged material parameters influence the dispersion solution, but also the amount and size of aggregate particles. The study shows that Lamb waves propagate with different velocities in homogeneous and heterogeneous models and the difference increases with aggregate ratio and particle size, which is a particularly important observation for wave-based diagnostic methods devoted to concrete structures.

Numerical study of the influence of material parameters on the mechanical behaviour of a rehabilitated edentulous mandible

2014 ◽  
Vol 42 (3) ◽  
pp. 287-297 ◽  
Author(s):  
Louis-Marc Favot ◽  
Valérie Berry-Kromer ◽  
Mohamed Haboussi ◽  
Frédéric Thiebaud ◽  
Tarak Ben Zineb
Keyword(s):  
Mechanical Behaviour ◽  
Numerical Study ◽  
Material Parameters ◽  
Edentulous Mandible

Establishing Correlation between Leaf Spring Specifications and Camber Drop

2014 ◽  
Vol 660 ◽  
pp. 794-798
Author(s):  
Majdi Abdul Rani Ahmad ◽  
M.A. Mohamad Rozaidi ◽  
Sarat Chandra Dass ◽  
Srinivasa Rao Pedapati
Keyword(s):  
Mathematical Model ◽  
Regression Analysis ◽  
Processing Parameters ◽  
Automotive Application ◽  
Leaf Spring ◽  
Heavy Load ◽  
Spring Rate ◽  
The Difference ◽  
Gathering Data ◽  
Half Length

Manufacturing of leaf spring for automotive application to support heavy load vehicles such lorry and truck is a challenging process. This is due to the difficulty in fabricating the leaf spring exactly as per designed. The difference between the desired leaf spring shape and the actual fabricated shape is known as camber drop. The aim of this study is to establish the correlation between leaf spring specifications, camber drop and its processing parameters. The formulated equation can thus be used to predict the extent of camber drop and required action can be taken to reduce camber drop. This work was conducted by gathering data of variables suspected to influence camber drop, namely quenching camber, half-length of the spring, spring rate and end thickness of the spring. Regression analysis was conducted and the correlation between leaf spring’s specifications and camber drop is given. A mathematical model able to predict the extent of camber drop is formulated.

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