Finite Element Simulation of Crash Test and Crashworthiness with LS-Dyna, Abaqus and PAM-CRASH Including Airbag & Seat Belt Effectiveness, Electric Vehicles (EV), Trucks, Bus and eVTOL
FEA & CFD Based Simulation Design Analysis Virtual prototyping MultiObjective Optimization
Many real-world engineering situations involve severe loads applied over very brief time intervals. While testing is crucial to analyze these types of loading scenarios, it can be expensive and sometimes economically infeasible to conduct physical tests when the cost of each prototype is prohibitively high. Moreover, data from a single physical test can be insufficient and companies cannot afford to conduct several of them for more detailed information.
Crashworthiness focuses on occupant protection to reduce the number of fatal and serious injuries. This research is responsible for developing and upgrading test procedures for evaluating motor vehicle safety. Crashworthiness research encompasses new and improved vehicle design, safety countermeasures and equipment to enhance occupant safety.
Finite Element Analysis (FEA) has been the trend in virtual crash design over the last decade. The predictive capabilities of FEA allow engineers to fully understand a crash event in a virtual environment, thus limiting the number of physical tests that need to be executed and thus saving costs.
Enteknograte engineers simulate the crash safety with innovative CAE and virtual prototyping available in the non-linear structural codes: LS-DYNA, PAM-CRASH, RADIOSS and ABAQUS. We offer advanced FEA modeling consultancy services. We are experienced with automotive crash safety and consumer crash test protocols such as (frontal impact), (side impact), IIHS and EuroNCAP. Our engineers have Tier1 backgrounds in FEM (Finite Element Method) and are fluent in the codes: LS-DYNA, PAM-CRASH, RADIOSS and ABAQUS.
Occupant Restraint Systems: Seatbelt assembly design
Occupant restraint systems are intended to control occupant motion within the vehicle during the crash. Occupant restraint system technologies (e.g. air bags, seat belts, seats, etc.) are continually advancing and are a major contributor to mitigating crash fatalities and injuries. Our Finite element simulation service can be used to demonstrate compliance with safety standards and regulations for seat belts, such as FMVSS 209 or ECE R16. By simulating the performance of the seat belt under various loading conditions, engineers can provide objective data to regulatory agencies to demonstrate compliance with safety standards. However, a significant number of crash injuries still occur, and efforts are ongoing to further improve restraint effectiveness. Occupant restraint system development continues to evolve as new regulations and consumer demand drive more complex solutions:
- Seatbelt assembly design: Optimize the design of the entire seatbelt assembly, including the attachment points, webbing routing, and geometry of the seat belt anchorages
FEA of Frontal Crash Protection
Frontal crashes are a major source of injuries and fatalities in the field. we use FEA dummies to evaluate occupant protection in frontal impact crash test. These efforts study occupant response, possible implications for smaller occupants, and restraint effectiveness for a rear seat passenger:
- Determination of Frontal Offset Test Conditions Based on FEA Crash Data
- FEA Approaches to Occupant Response
Small Overlap / Oblique Crashes
Studies show that fatalities still happen with vehicles equipped with safety belts and airbags in both small overlap and oblique crashes. Small overlap crashes are crashes with all the damage outside the main longitudinal member. Oblique crashes engage one of the main longitudinal members and cause the occupant to move in an oblique manner. Therefore, the agency is trying to develop test procedure to reduce fatalities and injuries in these two crash modes.
Enteknograte assisted a startup company in investigating the fracture pattern of a innovative Concrete-based designed Jersey barrier crash test behavior.
FEA of Airbag Effectiveness in Crash Test
Finite element simulation (FEA) is a powerful tool used in the automotive industry to design and test airbag systems. FEA allows engineers to simulate the behavior of airbags during a collision, including the inflation process and the interaction between the airbag and the vehicle occupants. The deformation mechanism of vehicles can be analyzed in full frontal, offset frontal and side impact scenarios.
Enteknograte use non-linear structural codes Ansys LS-DYNA, PAM-CRASH, RADIOSS and ABAQUS program to FEA of Airbag effectiveness in Crash Test and its effectiveness studied in dummy in different position and compliance with safety standards such as the Federal Motor Vehicle Safety Standard (FMVSS) 208 , FMVSS 214 and EuroNCAP . The simulation results could be compared with actual crash test data of the corresponding vehicles. Reliable Numerical Simulation reduce the number of crash tests required during the automobile design process.
Some of the key aspects of airbag design that can be modeled using Finite Element:
Airbag deployment: FEA simulations can be used to predict the timing and force of airbag deployment based on the impact speed, angle, and direction. This information can be used to optimize the design of the airbag inflator and cushion to provide the necessary protection to the occupants. ‘Airbag Module Deployment Test Procedure J1630’ is SAE Recommended Practice, describes a method to be used for the static deployment of airbag module assemblies. The results obtained from the deployment tests will be used to verify compliance with design requirements and/or specifications, and for other engineering purposes such as module performance comparisons, and/or CAE input or validation. The purpose for this procedure is to describe recommended test methods to ensure, to the extent possible, reliable and reproducible test results for driver airbag modules, passenger airbag modules, or other airbag modules (e.g., side airbags, roof rail airbags, knee bolster airbags, etc.).
Airbag cushion behavior: FEA simulations can model the behavior of the airbag cushion during deployment, including its deformation and stress distribution. This information can be used to optimize the cushion material and thickness to ensure that it provides maximum protection to the occupants.
Interaction with occupants: FEA simulations can also be used to model the interaction between the airbag and the vehicle occupants during a collision. This includes predicting the forces and stresses on the occupant’s body, as well as the risk of injury from the airbag itself.
Multi-airbag systems: FEA simulations can be used to design and optimize multi-airbag systems, including side impact airbags and curtain airbags. These simulations can model the interaction between multiple airbags and their impact on the occupants.
Advanced Air Bag Technology Research, Air Bag Aggressivity Study, Side Airbag Out-of-Position FEA Study.
Heavy Trucks Crash Test Simulation
Heavy Truck safety is focused on occupant safety and underride guards. Heavy truck occupant safety examines the causes of fatality and injury for heavy truck occupants, while truck underride research identifies the characteristics of underride events and contributing factors.
- Truck Underride
- Truck Occupant Safety
School Bus Crashworthiness & Crash Test
The governments try to ensure children safety in School Bus. But for investigation of crash effect and unwanted occurrences on children and level of injury, Finite element Method must be used to record force that transfer to the body in School bus and studying the absorbing mechanism and its level
Head injury criterion
The head injury criterion (HIC) is a mathematical formula that uses acceleration data to estimate the potential for head injury during an impact event. The HIC is commonly used in the automotive industry to evaluate the safety of vehicles, but it can also be applied to other products like personal protective gear and sports equipment.
The NHTSA and Insurance Institute for Highway Safety both use the HIC to evaluate the safety of vehicles and assign safety ratings. The NHTSA uses the HIC to determine the star rating for automobile safety, with a lower HIC value indicating a lower risk of head injury. The Insurance Institute for Highway Safety uses the HIC as one of several criteria to determine the safety ratings of vehicles, including the Top Safety Pick and Top Safety Pick+ awards. The maximum allowed HIC value of 700 under the U.S. advanced airbag regulation reflects the importance of limiting head injury risk in automotive crashes.
It’s worth noting that the HIC is just one of several metrics used to assess head injury risk, and it has some limitations. For example, it does not account for the rotational forces that can contribute to traumatic brain injuries. Nonetheless, the HIC remains a useful tool for evaluating the safety of various products and promoting the design of safer products.
EVs (Electric Vehicle) crash test FEA simulation and battery package crashworthiness analysis
Electric vehicles (EV) including battery electric vehicles (BEVs), hybrid-electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs) need to be safe – even in the unfortunate event of an accident. One of the critical concerns is the risk of fire that arises when lithium-ion cells are potentially damaged during a crash. The impact forces and structural deformation experienced during a crash can lead to cell damage and potential thermal runaway, which may result in a fire hazard. Therefore, it is crucial to simulate and analyze the crashworthiness of the electric vehicles and battery package to ensure its structural robustness and minimize the risk of fire.
In the USA, FMVSS 305 specifically focuses on electric-powered vehicles and sets requirements for the protection of vehicle occupants from high-voltage sources. This regulation is used in conjunction with FMVSS 208, FMVSS 214 (side impact), and FMVSS 301 (rear, rigid barrier and deformable barrier impact tests) for electric vehicles crashworthiness analysis. Regulation No. 100 (UN/ECE R100) is a United Nations Economic Commission for Europe (UNECE) regulation that establishes uniform provisions concerning the safety of electric and hybrid vehicles, including crash testing requirements.
By conducting finite element simulation, our engineers can gain insights into the performance of the electric vehicles (EV) and battery system under various crash scenarios. This information is invaluable for EV manufacturers to design safer battery enclosures, develop appropriate energy management systems, and implement effective safety measures to mitigate the risk of fire or other safety concerns.
We also offer crash test finite element simulation for other components according to the following standards: ECE-R11 (door latch), ECE-R16 (safety belts, restraint systems), ECE-R17 (seats), ECE-R44 (child restraint system), FMVSS 201 (occupant protection), EN 1789 (stretcher) and ISO 7176-19 standard (wheelchair).
eVTOLs crashworthiness design
Occupant safety is an integral part of the design, development, and operation of urban air mobility (UAM) systems. Emergency landing conditions design requirements specified in (Code of Federal Regulations) (Certification standard ) may not provide the level of safety for eVTOL vehicles.
The successful implementation of the UAM market will require emergency landing concepts that address real-world safety expectations. An integrated safety development process will help you maintain survivable volume, minimize deceleration loads to occupants, maintain egress paths and evaluate retention items of mass. Enteknograte engineers optimize eVTOL aircraft crashworthiness from the conceptual design stage using most advanced computational tools.
How multibody models and optimization tools can be used to define integrated safety concepts for:
- Landing gear and airframe crashworthiness
- High-energy absorbing seats, and advanced restraints
- Cabin subfloor structures
- Energy-absorbing landing and take-off sites
Defense Technical Information for Aircraft Crash Survival Design Guide
This five volume publication has been compiled to assist design engineers in understanding the design considerations associated with the development of crash resistant U.S. Army aircraft. A collection of available information and data pertinent to aircraft crash resistance is presented, along with suggested design conditions and criteria.
The five volumes of the Aircraft Crash Survival Design Guide cover the following topics Volume I – Design Criteria and Checklists Volume II – Aircraft Design Crash Impact Conditions and Human Tolerance Volume III – Aircraft Structural Crash Resistance Volume IV – Aircraft Seats, Restraints, Litters and CockpitCabin Delethalization and Volume V – Aircraft Postcrash Survival. This volume Volume III contains information on the design of aircraft structures and structural elements for improved crash survivability.
Current requirements for structural design of U.S. Army aircraft pertaining to crash resistance are discussed. Principles for crash-resistant design are presented in detail for the landing gear and fuselage subject to a range of crash conditions, including impacts that are primarily longitudinal, vertical or lateral in nature and those that involve more complicated dynamic conditions, such as rollover. Analytical methods for evaluating structural crash resistance are described:
- Aircraft Crash Survival Design Guide: Design Criteria and Checklists.
- Aircraft Crash Survival Design Guide: Aircraft Design Crash Impact Conditions and Human Tolerance.
- Aircraft Crash Survival Design Guide: AIRCRAFT STRUCTURAL CRASH RESISTANCE
- Aircraft Crash Survival Design Guide: Aircraft Seats, Restraints, Litters and Cockpit/Cabin Delethalization
- Aircraft Crash Survival Design Guide: Aircraft Postcrash Survival
Dummies for crash Test Simulation:
- Frontal impact dummies
- Hybrid II (50th percentile) rigid dummy for aeronautics applications
- Express Hybrid III 50th, & 5th percentile dummies
- Hybrid III 50th, 95th & 5th percentile dummies
- Side impact dummies:
- ES2 & ES2-re
- FTSS SID-IIs SBL C & D
- US SID
- SIDHIII
- WorldSID 50%
- WorldSID 5%
- Rear impact dummy
- BIORID IIg
- Child dummies
- Hybrid III 6 years
- Hybrid III 10 years
- P series 3, 6 and 10 years, 18 months
- Q series 3 years
- CRABI 12 months
- Pedestrian impactors
- Head (EEVC adults and Child, FMVSS 201)
- Pedestrian Head forms EEVC
- Lower leg EEVC impactor
- Upper leg EEVC impactor
- Standing HIII 50th rigid dummy
- Standing HIII child 6 years rigid dummy
- Human dummy model
- Complete human model: Humos2
- Human head, leg and foot models
- Barriers :
- Frontal barriers
- ODB (ECE 94 frontal regulation) solid & shell models
- PDB V8XT proposed by EEVC WG 15 for crash impact compatibility – shell & solid models
- TRL full width (consumer information test NCAP) – shell & solid models
- Side barriers
- NHTSA FMVSS 214 – solid & shell models
- Progress ECE 95– solid & shell models (Cellbond)
- AEMDB V3.9 = new proposal to update regulation EEVC W13 – solid & shell models (Cellbond)
- IIHS SUV Barrier – solid & shell models (Cellbond)
- Rear barriers
- RCAR IIHS low impact
- US Rear impact barrier FMVSS 310
- Rear impact ECE barrier
