Impact & Crash Finite Element Analysis

Impact and crash finite element analysis involve using computer simulations to model and analyze how products behave when subjected to impact loads, collisions, and crashes. It is used in a variety of industries for:

• Automotive – To evaluate vehicle crashworthiness and optimize crash structures to improve occupant safety. FE simulations can model impacts with barriers, other vehicles, and pedestrians.
• Aerospace – To design impact-resistant components like fan blades, engine cases, and fuselages that withstand impacts from debris, tool drops, and bird strikes.
• Consumer products – To ensure products like cell phones, laptops, and sporting goods can withstand drop tests and impacts during use and transportation.
• Industrial equipment – To optimize the durability and damage resistance of machinery that may experience impact loads during operation.
• Marine – Designing ship hulls and superstructures to withstand impacts from waves, icebergs, and debris in the water.
• Railway – Designing train carriages to withstand impacts from collisions.
• Oil & gas – Designing offshore platforms and structures to withstand impact loads from waves, dropped objects, and vessel collisions.
• Architecture & Construction – Designing bridges to withstand impact loads from vehicle collisions.

Impact & Crash Simulation

Our engineering company has a special ability in impact & crash finite element analysis such as:

• Full vehicle crash tests,
  • Frontal impacts – Collisions with barriers to test compatibility and occupant safety.
  • Side impacts – Collisions with other vehicles to evaluate door intrusion, seat performance and injuries.
  • Rollover tests – Simulating vehicle rollovers to analyze roof crush resistance.
  • Rear impact tests – Collisions from behind to study fuel spillage, occupant load paths and safety.
• Component crash tests
  • Bumper beam crash tests – To analyze stresses, energy absorption and performance.
  • Seat frame crash tests – To determine seat integrity, load paths and failure modes.
  • Front-end crash tests – To optimize crush zones, engine displacement and front-end structure.
• Simplified crash tests
  • Equivalent mass models – Where components are represented by lumped masses and springs.
  • Impactor tests – Where components are impacted by a rigid object to determine failure loads.
• Passive safety crash test
  • Airbag deployment simulations
  • Seatbelt pretensioner analysis
  • Child seat performance testing
• Comparative crash tests – These compare the crash performance of different design variations to optimize vehicle designs.

Crash FE models and simulations span a wide range from full vehicle tests to simplified component tests to analyze passive safety devices and optimize crush characteristics. The specific type of crash test or simulation depends on the objectives, level of detail required and capabilities.

other practical examples of impact simulation include:

1. Low-velocity impact – These involve relatively slow impacts in the 1-10 m/s range. Examples include:

• Drop tests – Components are dropped from a specific height to simulate impacts during use.

• Tool impacts – Components experience impacts from falling tools or objects.

• Pneumatic ram impacts – Components are impacted by a pressurized ram at controlled velocities.

2. High-velocity impact – These involve faster impacts in the 10-500 m/s range. Examples include:

• Ballistics testing – Components are impacted by projectiles to test penetration resistance.

• Bird strikes – Aircraft structures are modeled to determine impact resistance.

• Crash testing – Vehicles experience impacts at highway speeds.

Material Behavior

Materials experience very high strain rates when experiencing impact phenomena. Determining the mechanical behavior of materials at these strain rates requires accurate and precise FE simulations. In BanuMusa R&D, the necessary techniques such as the Hopkinson test machine (Split Hopkinson Pressure Bar (SHPB)), material model calibration, and validation of studies and tests are used.

Failure Mechanism

The main failure mechanisms that can occur in the crash and impact finite element analysis include:

1. Plastic deformation – Components undergo permanent deformation beyond their elastic limits. This can lead to a loss of functionality. Plastic strain measurements are used to indicate failure.
2. Yielding – The material starts yielding and deforming plastically. Initial yield locations indicate places of high stress under impact loads.
3. Buckling – Under high-impact loads, components can buckle and lose structural integrity. This is a potential failure mode to predict.
4. Fracture – Components experience cracking and breaking of material, either locally at stress concentrations or fully across sections. Crack propagation is modeled.
5. Material damage – Progressive damage models can be used to predict localized material degradation and erosion due to impacts.
6. Rupture – Components experience complete tearing or shearing under impact loads. Rupture criteria based on strain, stress or energy are defined.
7. Delamination – In composites, individual plies detach from each other due to inter-laminar shear stresses induced by impacts. This degrades stiffness.
8. Fiber breakage – In composite materials, fiber fractures occur under impact loads. Failure criteria based on fiber strains can be defined.
9. Occupant injury – In vehicle crash simulations, injury criteria are defined to determine the risk of occupant fatality or severity of injury.
10. Energy absorption – Components are deemed to have failed if they cannot absorb a sufficient portion of the impact energy through deformation, damping or other mechanisms.

 

Our company uses advanced methods to predict the failure of various materials. The latest models of material failure, coding in finite element analysis software, and calibration of material behavior are some of the measures used to achieve more accurate results. We also have sufficient experience in modeling and predicting progressive failure, as well as mechanisms and connections such as bolts, joints, and snap fittings.

Customers from the petrochemical, automotive, packaging, rail, and polymer industries use the BanuMusa R&D crash & impact finite element analysis services.