CME Activities

1. CME Activities • Define reporting procedures for simulations (data output, variables, etc) • Define an objective validation procedure for simulations • Define model requirements for test vehicles and road equipment • Define requirements for Analyst Competence / Quality Control 1 NCHRP_22_24 January 22 2007

2. CM/E Structure Completed • Currently the CM/E proposes a computational standard structure parallel to EN1317 • Part 1: Common Reference Information and Reporting • Part 2: Vehicle Models • Part 3: Test Article Models • Part 4: Validation Procedures • Part 5: Accreditation On going Current Focus Not Started 2 NCHRP_22_24 January 22 2007

3. CM/E Strategy • The implementation of Computational Mechanics in standardisation is anticipated in the following manner: • 1) Documentation and validation of test vehicle models • 2) Documentation and proof of performance of test article models • 3) Validation of test article model against full scale experimental data • 4) Simulation of test article for standardisation • Possible implementation of CM/E into a modified products approcal process is demonstrated in the following slide – at least 2 reports would be submitted to a notified body with supporting references (to establish the model suitability) • NOTE: This is only a proposal for using CM/E and is not an approved standard for its implementation 3 NCHRP_22_24 January 22 2007

4. CM/E Overview NOTIFIED BODY Original Product Crash Test Model Report of Original Product Library of Pre-Approved Models Analogous to Test Vehicle Vehicle model Vehicle validation report Test Article validation report Test article model Test article Documentation Proof of computation quality Type Approval Modified Product Crash Test Unique Model for Each Modification Modification of products Simulation report 4 NCHRP_22_24 January 22 2007

5. Work Plan (1): Validation Procedures Objective validation procedures are in development • Marco (PoliMi) has been investigating the Round Robin Data collected in ROBUST and is proposing some validation procedures for comparing test and simulation output • Further development of the validation procedures is moving slowly and no draft document is available yet. 5 NCHRP_22_24 January 22 2007

6. Work Plan (2): Vehicle Modelling A document is being submitted to TG1. It contains general state of the art procedures as well as “proof of suitability” checks. • State of the art – basic modelling techniques are presented so that a computer model can be assessed in terms of its construction. This is informative only as it is difficult read an input file. • Component “Validation” tests are presented as a method to demonstrate that a model has the basic requirements to be used in a full scale crash test. Basic vehicle manoeuvring and suspension loading are used to demonstrate model stability and proper function. • The document is currently oriented towards Finite Element models and uses LS-DYNA as a reference example. Some Multi-body dynamics information is also presented. 6 NCHRP_22_24 January 22 2007

7. Work Plan (3): Test Article Modelling A draft document has been submitted to TG1. It contains general state of the art procedures as well as “proof of suitability” checks. • State of the art – a questionnaire of current modelling practice was distributed to members. Information on the modelling techniques, as well as the component tests used to validate the models, was collected. This is informative only as it is difficult read an input file and cannot be generalized for all test articles (barriers, terminals, etc). • Test article model suitability is assessed through component tests and documentation of model components. Stress contour plots must be presented to identify if any unrealistic material performance is present. 7 NCHRP_22_24 January 22 2007

8. Work Plan (4): Reporting • The reporting procedure for computer simulations is dependent on the final documentation developed for the validation process. • The type of reporting structure will be determined by the final implementation procedure for CM (as presented earlier) • An example of the information necessary is presented in the following slide 8 NCHRP_22_24 January 22 2007

9. Validation Reporting • Simulation institute • Report number • Client • Test item • - Detailed description of the full scale tested item • - Description of the test item model • Simulation software • Post-processing software • Test type • Vehicle model • Results • Result requirements • Result discussion 9 NCHRP_22_24 January 22 2007

10. Work Plan (5): Analyst Accreditation • Accreditation is an open issue that still must be addressed by the group • There is nothing to report at this time. 10 NCHRP_22_24 January 22 2007

11. Time Frame • CM/E finalised the vehicle and test object modelling documents (Parts 2&3) • These documents should be revised at regular intervals • Validation procedures still require research • Further analysis of the Round Robin data in ROBUST is a necessary input • Difficult to predict the delivery of a draft procedure – possibly 2007 11 NCHRP_22_24 January 22 2007