Material Model Development of Sandwich Composite: Numerical-Experimental Investigation of Head Dummy Impacting at Vehicle Interior Components

2019 ◽  
Vol 827 ◽  
pp. 55-60
Author(s):  
A. Vettorello ◽  
G.A. Campo
Keyword(s):  
Numerical Models ◽  
Fibre Composite ◽  
Model Development ◽  
Material Model ◽  
Sandwich Composite ◽  
Crash Analysis ◽  
Vehicle Interior ◽  
Polymeric Foam ◽  
Glass Fibre Composite

This paper shows the applicability of a non-linear Finite Element (FE) methodology to analyse the elasto-plastic behaviour and the energy absorption of a padding noise-protection material applied to the vehicle interior components. This material is a sandwich built from alternating layers of polymeric foam and of glass fibre composite. The approach considers two design steps. The first one involves the experimental characterization of the material while the latter deals with the assessment of the numerical models validated for a full-vehicle crash analysis.

Treatment system response to transient AOX (adsorbable organic halogen) loadings

1997 ◽  
Vol 35 (2-3) ◽  
pp. 85-91
Author(s):  
D. A. Barton ◽  
J. D. Woodruff ◽  
T. M. Bousquet ◽  
A. M. Parrish
Keyword(s):  
Paper Industry ◽  
Model Development ◽  
Operating Conditions ◽  
System Response ◽  
Additional Information ◽  
Organic Halogen ◽  
Aox Removal ◽  
Variable Operating Conditions ◽  
Plant Shutdown

If promulgated as proposed, effluent guidelines for the U.S. pulp and paper industry will impose average monthly and maximum daily numerical limits of discharged AOX (adsorbable organic halogen). At this time, it is unclear whether the maximum-day variability factor used to establish the proposed effluent guidelines will provide sufficient margin for mills to achieve compliance during periods of normal but variable operating conditions within the pulping and bleaching processes. Consequently, additional information is needed to relate transient AOX loadings with final AOX discharges. This paper presents a simplistic dynamic model of AOX decay during treatment. The model consists of hydraulic characterization of an activated sludge process and a first-order decay coefficient for AOX removal. Data for model development were acquired by frequent collection of influent and effluent samples at a bleach kraft mill during a bleach plant shutdown and startup sequence.

A validated railway vehicle interior layout with multibody dummies and finite element seats models for crash analysis

2021 ◽  
Author(s):  
Jorge Ambrósio ◽  
Marta Carvalho ◽  
João Milho ◽  
Susana Escalante ◽  
Roberto Martín
Keyword(s):  
Finite Element ◽  
Railway Vehicle ◽  
Crash Analysis ◽  
Vehicle Interior

Thermal decomposition of multilayer honeycomb core laminate sandwich composite panels in cone calorimeter apparatus – Effect of the top decomposed layer

2021 ◽  
pp. 002199832199087
Author(s):  
Hussain Najmi ◽  
Jocelyn Luche ◽  
Thomas Rogaume
Keyword(s):  
Cone Calorimeter ◽  
Single Layer ◽  
Heat Fluxes ◽  
Decomposition Process ◽  
Phase Iii ◽  
Sandwich Composite ◽  
Back Surface ◽  
Multilayer Composite ◽  
In Fire

Multilayer composite materials are frequently used in aircraft interiors. Even though they have high properties (such as physical, chemical and mechanical properties), their application is limited due to lack of knowledge of their decomposition process and on the interaction between different layers in fire. In the present work, two types of composites with 3 and 4 layers are studied. The fire characterization of multilayer composite is studied in 3 different phases using ISO-5660 cone calorimeter at two heat fluxes (35 and 50 kW.m−2). Phase-I mainly concentrates on the decomposition of single layer materials (paint, laminate and honeycomb) while in phase-II and phase-III, different assemblies are formed using a single layer material and studied in the same experimental configuration. In all the three phases, back surface temperatures of the materials or assemblies are measured and analyzed with different gas productions which allow to understand the dynamics of the decomposition process. The finding from the cone calorimeter study suggests that the ignition primarily depends on the top layer behavior of the composite. The permeability analysis on the top layer of the composite confirms that decomposed layer of paint offers more resistance to the volatile gases escaping from the composite. At the end of the study, thermal conductivity is determined and the ignition temperature of both the composite is determined.

scholarly journals Optimization of Piezo-fibre Composite with IDE Embedded in a Multilayer Glass Fibre Composite

2014 ◽  
Vol 6 ◽  
pp. 1207-1216 ◽  
Author(s):  
B. Vinod Kumar ◽  
Anoop Raveendran ◽  
Victor Davis
Keyword(s):  
Glass Fibre ◽  
Fibre Composite ◽  
Glass Fibre Composite

Influence of Phase Transformations on Residual Stresses in Welded Structures

2013 ◽  
Author(s):  
R. J. Dennis ◽  
R. Kulka ◽  
O. Muransky ◽  
M. C. Smith
Keyword(s):  
Phase Transformation ◽  
Residual Stresses ◽  
Phase Transformations ◽  
Numerical Models ◽  
Material Model ◽  
Transformation Model ◽  
Austenitic Steels ◽  
Beam Specimen ◽  
Welded Structures ◽  
The Impact

A key aspect of any numerical simulation to predict welding induced residual stresses is the development and application of an appropriate material model. Often significant effort is expended characterising the thermal, physical and hardening properties including complex phenomena such as high temperature annealing. Consideration of these aspects is sufficient to produce a realistic prediction for austenitic steels, however ferritic steels are susceptible to solid state phase transformations when heated to high temperatures. On cooling a reverse transformation occurs, with an associated volume change at the isothermal transformation temperature. Although numerical models exist (e.g. Leblond) to predict the evolution of the metallurgical phases, accounting for volumetric changes, it remains a matter of debate as to the magnitude of the impact of phase transformations on residual stresses. Often phase transformations are neglected entirely. In this work a simple phase transformation model is applied to a range of welded structures with the specific aim of assessing the impact, or otherwise, of phase transformations on the magnitude and distribution of predicted residual stresses. The welded structures considered account for a range of geometries from a simple ferritic beam specimen to a thick section multi-pass weld. The outcome of this work is an improved understanding of the role of phase transformation on residual stresses and an appreciation of the circumstances in which it should be considered.

A new ensemble-based statistical methodology to verify changes in weather and climate models

2021 ◽  
Author(s):  
Christian Zeman ◽  
Christoph Schär
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Numerical Models ◽  
Hypothesis Test ◽  
Model Development ◽  
Atmospheric Model ◽  
Statistical Hypothesis ◽  
Model Parameters ◽  
Rounding Errors ◽  
Weather And Climate

<p>Since their first operational application in the 1950s, atmospheric numerical models have become essential tools in weather and climate prediction. As such, they are a constant subject to changes, thanks to advances in computer systems, numerical methods, and the ever increasing knowledge about the atmosphere of Earth. Many of the changes in today's models relate to seemingly unsuspicious modifications, associated with minor code rearrangements, changes in hardware infrastructure, or software upgrades. Such changes are meant to preserve the model formulation, yet the verification of such changes is challenged by the chaotic nature of our atmosphere - any small change, even rounding errors, can have a big impact on individual simulations. Overall this represents a serious challenge to a consistent model development and maintenance framework.</p><p>Here we propose a new methodology for quantifying and verifying the impacts of minor atmospheric model changes, or its underlying hardware/software system, by using ensemble simulations in combination with a statistical hypothesis test. The methodology can assess effects of model changes on almost any output variable over time, and can also be used with different hypothesis tests.</p><p>We present first applications of the methodology with the regional weather and climate model COSMO. The changes considered include a major system upgrade of the supercomputer used, the change from double to single precision floating-point representation, changes in the update frequency of the lateral boundary conditions, and tiny changes to selected model parameters. While providing very robust results, the methodology also shows a large sensitivity to more significant model changes, making it a good candidate for an automated tool to guarantee model consistency in the development cycle.</p>

Monotonic Behaviors of Steel Frames with Sandwich Composite Panel Infills: Theoretical and Numerical

2012 ◽  
Vol 193-194 ◽  
pp. 1424-1428
Author(s):  
Miao Liu ◽  
Yan Fei Sun ◽  
C.X. Qiu ◽  
He Tao Hou
Keyword(s):  
Structural Engineering ◽  
Theoretical Study ◽  
Numerical Models ◽  
Steel Frames ◽  
Composite Panel ◽  
Sandwich Composite ◽  
Actual Structure ◽  
Equivalent Strut ◽  
Cross Section Area ◽  
Section Area

Abstract: Analysis of infilled frames is one of the most complicated problems in the structural engineering field. This complication is mainly attributed to the existence of the variety and complex of the infills and the difficulty in modeling the infill-frames interaction. In the present paper, with the aim to study the integral behavior of the single-story single-bay steel frames with sandwich composite panel infills, a proper computational model (the panel is simplified into an equivalent pin-jointed diagonal strut) is proposed. In the theoretical study, both of the panels and steel frames are assumed to be in the linear elastic state for simplicity’s sake, and then the cross-section area of the equivalent strut is obtained by imposing the initial lateral stiffness of actual structure equal to that of simplified model. As a support of the discussion, several numerical models under monotonic lateral loadings are performed by software ABAQUS, in order to verify the theoretical analysis. Finally, results from theoretical study and numerical modeling are compared, which give a satisfactory correlation between them.

Sign in / Sign up

Export Citation Format

Share Document