CEN/TR 16303-3:2012
(Main)Road restraint systems - Guidelines for computational mechanics of crash testing against vehicle restraint system - Part 3: Test Item Modelling and Verification
Road restraint systems - Guidelines for computational mechanics of crash testing against vehicle restraint system - Part 3: Test Item Modelling and Verification
The aim of this Technical Report is to provide a step-by-step description of the development process of a reliable VRS model for the simulations of full-scale crash tests.
Rückhaltesysteme an Straßen - Richtlinien für Computersimulationen von Anprallprüfungen an Fahrzeug-Rückhaltesysteme - Teil 3: Modellierung des Prüfgegenstands und Überprüfung
Ziel dieses Technischen Berichts ist, eine schrittweise Beschreibung für den Entwicklungsprozess eines Fahrzeugrückhaltesystems zur Simulation voll maßstäblicher Anprallprüfungen festzulegen.
Dispositifs de retenue routiers — Recommandations pour la simulation numérique d'essai de choc sur des dispositifs de retenue des véhicules — Partie 3 : Composition et vérification des modèles numériques de dispositifs d'essai
Le présent Rapport technique vise à fournir une description pas à pas du processus de mise au point d'un modèle de VRS fiable pour la simulation d'essais de choc en vraie grandeur.
Oprema cest - Smernice za računalniške simulacije preskusnih trčenj v sisteme za zadrževanje vozil - 3. del: Oblikovanje preskusnega vzorca in preverjanje
Ta del tehničnega poročila je namenjen obveščanju uporabnika o vseh potrebnih informacijah za razvoj celovitega in učinkovitega numeričnega modela preskusnega vozila za pravilno simulacijo trčenja. Modeli sistemov za zadrževanje vozil (VRS) predstavljajo preskusni vzorec v certifikacijskem preskusu v skladu s standardom EN 1317. Model mora natančno prikazati delovanje sistema za zadrževanje vozil, da se lahko merila učinkovitosti iz standarda EN 1317 izločijo iz simulacije trčenja vozila z modelom sistema za zadrževanje vozil. Simulacija sistema za zadrževanje vozil se lahko oceni le v kombinaciji z validiranim modelom vozila iz standarda CEN/TR 16303-2. Obstajajo različne vrste sistemov za zadrževanje vozil, ki lahko vsebujejo dele iz betona, kovine, plastike in kompozitnih materialov. Vsak sistem ima drugačne zahteve za oblikovanje, v spodnjem navodilu pa so opisane smernice, ki se uporabljajo za vse sisteme za zadrževanje vozil. Treba se je zavedati, da so zahteve za oblikovanje upogljivih sistemov za zadrževanje vozil precej drugačne od zahtev za oblikovanje togih sistemov, zato te niso zajete v to izdajo smernic. Ta dokument se trenutno osredotoča na metodologije simulacij končnih elementov. Tudi dinamične kode togega (ali večdelnega) sistema se uporabljajo pri razvoju sistemov za zadrževanje vozil. Zahteve za modele sistemov za zadrževanje vozil niso enake kot za pristop s končnimi elementi in morajo biti skladne z metodologijo. Na področju skupine CM/E še ni smernic za uporabo kod togega sistema; njihova uporaba pri zahtevi za certifikacijo ni priporočljiva, dokler niso podobno določene. Cilj tega tehničnega poročila je zagotoviti opis vseh korakov v postopku razvoja zanesljivega modela sistema za zadrževanje vozil za simulacije preskusnega trčenja v polnem obsegu.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2012
2SUHPDFHVW6PHUQLFH]DUDþXQDOQLãNHVLPXODFLMHSUHVNXVQLKWUþHQMYVLVWHPH]D
]DGUåHYDQMHYR]LOGHO 2EOLNRYDQMHSUHVNXVQHJDY]RUFDLQSUHYHUMDQMH
Road restraint systems - Guidelines for computational mechanics of crash testing against
vehicle restraint system - Part 3: Test Item Modelling and Verification
Rückhaltesysteme an Straßen - Richtlinien für Computersimulationen von
Anprallprüfungen an Fahrzeug-Rückhaltesysteme - Teil 3: Modellierung des
Prüfgegenstands und Überprüfung
Dispositifs de retenue routiers - Recommandations pour la simulation numérique d'essai
de choc sur des dispositifs de retenue des véhicules - Partie 3: Composition et
vérification des modèles numériques de dispositifs d'essai
Ta slovenski standard je istoveten z: CEN/TR 16303-3:2012
ICS:
13.200 3UHSUHþHYDQMHQHVUHþLQ Accident and disaster control
NDWDVWURI
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT
CEN/TR 16303-3
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2012
ICS 13.200; 93.080.30
English Version
Road restraint systems - Guidelines for computational
mechanics of crash testing against vehicle restraint system -
Part 3: Test Item Modelling and Verification
Dispositifs de retenue routiers - Recommandations pour la Rückhaltesysteme an Straßen - Richtlinien für
simulation numérique d'essai de choc sur des dispositifs Computersimulationen von Anprallprüfungen an Fahrzeug-
de retenue des véhicules - Partie 3: Composition et Rückhaltesysteme - Teil 3: Modellierung des
vérification des modèles numériques de dispositifs d'essai Prüfgegenstands und Überprüfung
This Technical Report was approved by CEN on 7 November 2011. It has been drawn up by the Technical Committee CEN/TC 226.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16303-3:2012: E
worldwide for CEN national Members.
Contents
Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 General considerations on the modelling technique . 5
4 VRS model . 6
5 Verification of the model . 8
6 Collection Data . 10
Annex A Recommendations for the mesh of Finite Element VRS models addressed to crash
simulations . 11
Annex B Recommendations for development of Multi-Body VRS models addressed to crash
simulations . 14
Annex C Phenomena importance ranking table for test Items . 15
Bibliography . 19
Foreword
This document (CEN/TR 16303-3:2012) has been prepared by Technical Committee CEN/TC 226 “Road
equipment”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document consists of this document divided in five Parts under the general title: Guidelines for
Computational Mechanics of Crash Testing against Vehicle Restraint System:
Part 1: Common reference information and reporting
Part 2: Vehicle Modelling and Verification
Part 3: Test Item Modelling and Verification
Part 4:Validation Procedures
Part 5: Analyst Qualification
In preparation
Introduction
This part of this Technical Report is meant to provide the user with all the information necessary for the
development of a complete and efficient numerical model of a test item vehicle in order to properly simulate a
crash event.
The vehicle restraint system (VRS) models represent the test item in a certification test according EN 1317.
The model shall faithfully depict the performance of a VRS so that the performance criteria identified in
EN 1317 can be extracted from the simulation of a vehicle impact with the VRS model. The VRS simulation
can only be assessed in combination with a validated vehicle model described in CEN/TR 16303-2.
There are different types of VRS and they can incorporate concrete, metal, plastic, and composite materials in
their construction. Each system has different modelling requirements and the following manual describes the
guidelines applicable for all VRS. It is important to recognize that the requirements for modelling a deformable
VRS are significantly different from a rigid systems and the latter are not covered in this version of the
guidelines.
This document currently focuses on Finite Element simulation methodologies. Rigid body (or multi-body)
dynamic codes are also used in the development of a VRS. The VRS model requirements are not the same
as for the Finite Element approach and shall be consistent to the methodology. The CM/E group does not yet
have guidelines for the use of rigid body codes and their application for certification requirement cannot be
recommended until they are similarly defined.
1 Scope
The aim of this Technical Report is to provide a step-by-step description of the development process of a
reliable VRS model for the simulations of full-scale crash tests.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 1317-1, Road restraint systems — Part 1: Terminology and general criteria for test methods
EN 1317-2, Road restraint systems — Part 2: Performance classes, impact test acceptance criteria and test
methods for safety barriers including vehicle parapets
EN 1317-3, Road restraint systems — Part 3: Performance classes, impact test acceptance criteria and test
methods for crash cushions
ENV 1317-4, Road restraint systems — Part 4: Performance classes, impact test acceptance criteria and test
methods for terminals and transitions of safety barriers
EN 1317-5, Road restraint systems — Part 5: Product requirements and evaluation of conformity for vehicle
restraint systems
prCEN/TR 1317-6, Road restraint systems — Part 6: Pedestrian restraint system, pedestrian Parapets (under
preparation)
prEN 1317-8, Road restraint systems — Part 8: Motorcycle road restraint systems which reduce the impact
severity of motorcyclist collisions with safety barriers
CEN/TR 16303-2:2011, Road restraint systems — Guidelines for computational mechanics of crash testing
against vehicle restraint system — Part 2: Vehicle Modelling and Verification
CEN/TR 16303-4:2011, Road restraint systems — Guidelines for computational mechanics of crash testing
against vehicle restraint system — Part 4: Validation Procedures
3 General considerations on the modelling technique
3.1 General
Particular attention shall be paid on the geometrical description of the contact areas of the VRS model. Proper
geometry and material properties shall be used. The fixation of the VRS to the roadbed shall correspond to
the test conditions reflected by the standard and the application of the VRS. Modelling of any soil, asphalt,
concrete, etc. element should be documented. Simplifications as well as rigid soil conditions shall be justified
through empirical or engineering analyses independent of the computer model.
The model shall include all significant parts, the connections between the parts, and appropriate boundary
conditions.
3.2 Finite Element and Multi-body approaches
3.2.1 General
Two main modelling approaches can be considered, using two different analysis tools: the Finite Element
Method (FEM) and the Multi-Body (MB) approach. Both methods are widely known and broadly used in many
fields of engineering, including the Automotive Industry.
The first method allows the user to build a very detailed vehicle model and to assess global results such as
the barrier or vehicle performance in a crash test as well as the stress data in a local area of the vehicle. As a
counterpart, a FEM analysis requires significant computational costs, thus proving less valid for parametric
studies where a large number of simulations may be required.
Once the VRS model has been built, it shall be validated with simple tests, such as component tests and then
full-scale dynamic tests. Validation procedures are listed in a separate document (CEN/TR 16303-4). These
validation tests ensure the global response of the model is appropriate and any simplifications of the model
still reproduce the functionality of the system. Numerical stability of the model can be assessed during the
validation process. Subsequently, the model can be used to simulate full-scale crash tests within the
application areas accepted in EN 1317.
Furthermore Computation mechanics when validated can provide support in real life situations that are not
described within EN 1317.
3.2.2 Finite Element guidelines
Crash tests finite element (FE) simulations are usually run with a dynamic, non-linear and explicit finite
element code. Computer runtime is usually significant, with the order of 30-40 hours on a 2,4 GHz personal
computer for the simulation of a full-scale crash test with an effective simulated time of 0,25 second. In fact,
the model shall include not only the vehicle model, but also several meters of roadside barriers (depending on
the barrier type, up to 80 meters of barrier) to faithfully reproduce the interaction between the vehicle and the
barrier and the boundary conditions. The integration time step is controlled by the minimum dimension of the
smallest element of the FE mesh, therefore, the mesh size shall be a trade-off between the need for
geometrical and numerical accuracy and computational cost: large elements guarantee a high time step but
poor accuracy of the model and possible instabilities, while small elements give a better accuracy but a
smaller time step. General criteria for Finite Element modelling techniques are identified in Annex A. The most
significant parts of the VRS shall be modelled explicitly with a detailed mesh. Simplifications of certain
structures (bolts, slots, etc.) are acceptable if the appropriate functionality is incorporated. For example, bolted
connections can be replaced by beam elements if the appropriate failure characteristics of the beam elements
are incorporated.
3.2.3 Multi-body guidelines
The MB approach consists in modelling the VRS with a number of rigid bodies connected by means of joints
with specified stiffness characteristics. When reliable and validated data are available, the MB approach is
very useful to perform parametric studies or big test scenario, since the computational cost of the analysis can
be dramatically less than that of the corresponding FEM analysis.
4 VRS model
4.1 Component to be modelled
The majority of elements in a road restraint system lend themselves to direct geometric digitisation in a FE or
MB model. These elements are (but not limited to):
1) posts;
2) horizontal elements;
a. metal beams;
b. cables;
3) block-out beams / spacers;
4) bolted connections;
5) concrete elements;
6) soil.
General mesh specifications for FE method are listed in Annex A. These specifications are based on the date
of publication (March 2006) level of simulation activities in research and product development. As general
practice, the mesh size and arrangements shall permit the observed (or expected) deformed shape of the
parts. Once a mesh specification has been determined, it becomes a practical issue to determine to which
extent this mesh shall be applied to the entire test object. The level of detail required in the deformed parts
may not need to be applied to all structures that are not subject to local buckling phenomena or other high
stress gradients.
Recommendations for the development of Multi-Body VRS models, addressed to crash simu
...
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