DRAFT_SOLICITATION_WD001.pdf

U.S. ARMY TANK AUTOMOTIVE RESEARCH, DEVELOPMENT and ENGINEERING CENTER

COMPUTATIONAL SIMULATION & MOTION BASED TECHNOLOGY TEAM

ENGINEERING WORK DIRECTIVE (EWD)

EWD NO.: WD 0001

REV.: 0

PRIORITY: 1

DATE: 10/30/2015

CLASSIFICATION

WORK DIRECTIVE

UNCLASSIFIED

X

CONFIDENTIAL

SECRET

DATA

HARDWARE

RESTRICTIONS: None.

HUMAN SUBJECTS: Not required.

CONTRACT NO.: C.3.13.1

CONTRACTOR:

PROJECT TITLE: A modeling approach to effectively couple different computational codes for underbody ground vehicle blast simulations

START DATE: Upon award of WD 0001

COMPLETION DATE: 10 months after date of work directive award

OBJECTIVE: To develop a coupled computational model involving two different dynamics codes (LS-DYNA and MADYMO) to effectively utilize the best features of each code and thus enabling selective reduced order modeling operating along with higher fidelity content within a single simulation.

GENERAL/BACKGROUND: Improvised Explosive Devices (IEDs) pose significant threat to military ground vehicles and soldiers in the field. Due to the severity of forces exerted by a blast, ground vehicles may undergo multiple sub-events subsequent to IED explosion including local structural deformation of the floor, blast-off and slam-down. To understand injuries sustained by soldiers within vehicles subjected to blast events, it is imperative to analyze the impact of each sub-event on soldier injuries. Using traditional finite element analysis techniques to evaluate an entire event is inefficient, as calculation times may exceed several days for one simulation of up to 300 milliseconds. Traditional finite element methods are also incapable of accurately modeling events longer than 200 milliseconds due to error accumulation in the calculations. LS-Dyna is a computational solver that is widely used in the Army for underbody blast simulations.

On the other hand, there are reduced order models that are being developed which are computationally less expensive, run faster and, in general, are more stable than traditional finite element analysis techniques. However, these reduced order models do not have all the details of a high fidelity model and, hence, the solutions tend to be approximations of higher order or higher fidelity models. One computational tool for reduced order modeling and simulation is Mathematical Dynamic Models (MADYMO). MADYMO is a leading design and analysis software for vehicle occupant safety systems in the safety/crashworthiness industry. MADYMO is known for its fast and accurate calculations of injury risks and safety system performance, and for containing an accurate library of crash dummy & human body computer models.

This Work Directive is intended to develop a computationally efficient approach of coupling LS-Dyna and MADYMO which are on the opposite ends of the model fidelity spectrum. This coupling of MADYMO and LS- DYNA has been successfully performed in the automotive industry for vehicle frontal impact simulations where the vehicle structure is modeled using LS-DYNA to create high fidelity finite element structural models and the vehicle occupants have been modeled using MADYMO.

The contractor shall couple a model of a generic vehicle structure, which it shall develop using LS-DYNA, with a

Government-furnished occupant model, which will be provided by the COR NLT 15 calendar days after WD award, using MADYMO. The goal of this WD 001 determine the maximum potential reduction in run time that, when compared with a standard LS-DYNA model without MADYMO coupling, will enable design engineers to perform quicker analyses of proposed design changes while at the same time capturing the generic vehicle’s structure’s performance from the finite element model content.

The contractor shall perform the following tasks:

TASK 1: Using a Government-furnished finite element vehicle structure model in LS-DYNA of a generic TARDEC vehicle that the Contracting Officer’s Representative (COR) will provide to the contractor no later than (NLT) 15 calendar days after WD 001 award, the contractor shall prepare and deliver a finite element model to simulate the blast loading of the Government-furnished ground vehicle, caused by underbody blast no later than (NLT) 30 calendar days after WD 001 award. The contractor shall perform a vertical blast simulation using LS-DYNA to ensure that the high fidelity finite element (FE) structural model performs as needed for the MADYMO integration (reference Task 3] below). The blast loading used in the vertical blast simulation shall be applied using two (2) different methods: (i) CONWEP (a blast-loading method in LS-DYNA); and (ii) ALE-FSI (Arbitrary Lagrange- Eulerian Method – Fluid Structure Interface).

TASK 2: The contractor shall integrate a commercial 50th percentile Hybrid III occupant male crash-test dummy Finite Element (FE) model into the FE vehicle structural model cited in Task 1 using occupant positioning data provided by the COR. The COR will provide the occupant positioning data NLT 30 calendar days after WD 001 award. The contractor shall route a standard seatbelt (50mm wide by 1.2mm thick) around the occupant FE model and connect it to a minimum of three (3) vehicle anchor locations. The contractor shall perform two (2) under body blast simulations of vehicle with FE occupant, NLT four (4) months after WD 001 award. The COR will provide the specific blast loading requirements to be used in the two simulations NLT 30 calendar days after WD 001 award.

TASK 3: The contractor shall integrate a commercial 50th percentile Hybrid III occupant MADYMO model into the LS-DYNA FE vehicle structural model developed in Task 1, NLT seven (7) months after WD 001 award, using occupant positioning data provided by the COR. The COR will provide the occupant positioning data NLT 30 calendar days after WD 001 award. The contractor shall route a standard seatbelt (50mm wide by 1.2mm thick) around the occupant model and connect it to a minimum of three (3) vehicle anchor locations. The contractor shall develop two (2) separate models for seat belt system: (i) with MADYMO seat belt system; and (ii) FE seat belt system in LS-DYNA. The contractor shall perform two (2) under body blast simulations of vehicle with MADYMO occupant, NLT eight (8) months after WD 001 award. The contractor shall deliver all MADYMO-LS-DYNA-coupled models developed in Task 3 to the COR NLT 8 calendar months after WD001 award.

TASK 4: The contractor shall develop a technical report containing a detailed outline of the process undertaken to develop the models developed in Tasks 1, 2, and 3. The report shall describe each step in detail and explain the purpose(s) of each step and how it was achieved along with details on computational performance of the run times of all simulations conducted in Tasks 1, 2, and 3. The report shall also provide comparison of the occupant injury responses obtained from simulations conducted in Task 2 and Task 3. The contractor shall deliver the final version of the technical report to the COR NLT 15 calendar days prior to WD 001 completion in accordance with (IAW)

CDRL A001.

REPORTING/DELIVERABLE REQUIREMENTS:

Start of Work Meeting: A Start of Work meeting shall be held NLT 15 calendar days after WD 001 award IAW C.5.1 of the contract’s Statement of Work. At this meeting, the contractor shall present their planned approach to complete this WD effort. The contractor shall coordinate with the COR to schedule a specific location, date and time for the Start of Work meeting. The contractor shall provide meeting minutes IAW CDRL A003 and presentation materials IAW CDRL A007 to the COR.

Project Review Meetings: The contractor shall conduct quarterly (every three (3) months while a WD is active, starting after WD 001 award) project review meetings at the contractor’s facility, subcontractor or vendor facility, or other Government facility, as mutually agreed upon by the contractor and COR, IAW C.5.3 of the contract’s Statement of Work. The first project review meeting shall occur NLT three (3) months after WD award. The contractor shall provide meeting minutes IAW CDRL A003 and presentation materials IAW CDRL A007 to the

COR.

Monthly Progress Reports: The contractor shall submit written, monthly (every month after WD 001 award and while there is still an active WD on-going) “Contractor’s Progress, Status and Management Reports” IAW CDRL A001. The first report shall be delivered NLT one (1) month after WD 001 award.

Draft and Final Technical Reports and Final Briefing:

(a) The contractor shall deliver a draft and final technical report summarizing the work performed and the results and conclusions derived from this WD to the COR (IAW CDRL A002). The draft technical report shall be due NLT 30 calendar days prior to WD completion. The COR will have seven calendar days to review and either (i) approve the technical report or (ii) provide questions and comments. If the COR has questions and comments concerning the draft technical report, the contractor shall revise the draft to address them, producing a final technical report for delivery NLT 15 calendar days after receipt of COR’s questions or comments.

(b) The contractor (Principal Investigator or designated representative) shall present a related final briefing to the COR NLT 15 calendar days prior to WD completion. The contractor shall provide meeting minutes (IAW CDRL A003) and presentation materials (IAW CDRL A007) to the COR.

Modeling Deliverables: The contractor shall deliver all models and data files created and used in Tasks 1 - 3 (IAW CDRL A005). The contractor shall also deliver all executables and source code developed in these tasks

(IAW CDRL A006).

GOVERNMENT FURNISHED INFORMATION / EQUIPMENT / PROPERTY:

1. Finite element structural model in LS-DYNA of a generic ground vehicle (Task 1)

2. Occupant positioning data (Task 2 and 3)

3. Blast loading requirements (Task 2)

PREVIOUS

THIS CHANGE

TOTAL THIS REVISION

AUTHORIZED HOURS: 0

Labor Category

Labor 1

Labor 2

Labor 3

AUTH. HOURS:

AUTH. HOURS:

COST PRIOR THIS ACTION TOTAL

Composite Hourly Costs

Materials $ $ $

Subcontractor Costs $ $ $

Travel $ $ $

Totals WD 001 $ $ $

SUBMITTER (Technical Advisor):

GOV'T REVIEW (Project Engineer/COR):

GOV'T APPROVAL (Contracting Officer):