Short answer

When designing for impact absorption, consider the synergistic effects of material properties, geometric form, and validated simulation models to achieve targeted performance metrics.

Field: Final Production
Source: NASA STI Repository (National Aeronautics and Space Administration) (2015)
Method: Experimental testing and finite element simulation
Evidence: Strong effect

A sinusoidal foam sandwich energy absorber, utilizing hybrid carbon-Kevlar face sheets and a closed-cell foam core, successfully demonstrated its ability to limit floor-level acceleration to a target range of 25-40g in simulated helicopter crash scenarios. This final production research insight is drawn from a 2015 study published in NASA STI Repository (National Aeronautics and Space Administration). Using Experimental testing and finite element simulation, researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing for impact absorption, consider the synergistic effects of material properties, geometric form, and validated simulation models to achieve targeted performance metrics.

Study

Final ProductionHigh ImpactStrong effect

Sinusoidal Foam Sandwich Design Achieves Targeted G-Force Reduction in Crash Simulation

NASA STI Repository (National Aeronautics and Space Administration) · 2015

Key Findings

01The sinusoidal foam sandwich energy absorber met the design goal of achieving average floor-level accelerations between 25- and 40-g.
02Finite element simulations closely matched experimental results for load-displacement, acceleration-time history, and structural deformation.
03The design demonstrated effective energy absorption and controlled deformation under impact loading.

Application

Design takeaway

When designing for impact absorption, consider the synergistic effects of material properties, geometric form, and validated simulation models to achieve targeted performance metrics.

How to apply

When designing protective structures or impact mitigation systems, explore composite materials and geometric optimizations, validating designs with both physical testing and computational simulations.

Project actions

01When selecting materials for impact absorption, consider their energy-dissipating properties.
02Investigate how shape and geometry influence the structural response to impact.
03Utilize simulation software to predict and refine designs before physical prototyping.

Method & Evidence

AimTo evaluate the impact performance of a sinusoid-shaped foam sandwich energy absorber designed to limit floor-level acceleration during a helicopter crash.

MethodExperimental testing and finite element simulation

ProcedureComponent specimens of the energy absorber were subjected to quasi-static and dynamic crush testing. A full-scale subfloor beam incorporating the energy absorber was fabricated and tested via a vertical drop onto concrete. Finite element models were developed and simulations were run using LSDYNA to compare predicted and experimental results.

ContextAerospace engineering, specifically helicopter crashworthiness

Variables

IV["Shape of the energy absorber (sinusoidal vs. other)","Material composition (face sheets, foam core)"]

DV["Average floor-level acceleration (g-force)","Load-displacement response","Structural deformation and damage"]

CV["Drop height","Impact surface (concrete)","Overall airframe structure (in full-scale test)"]

Strengths & Limitations

Strengths

+Multi-level testing from component to full-scale simulation.
+Validation of simulation models against experimental data.
+Clear design goals and performance metrics.

Limitations

The cost and complexity of advanced materials and simulation software can be a barrier. Replicating the exact conditions of a real-world crash in a small-scale experiment is challenging.

Reliability & validity

The study's reliability is supported by the comparison of multiple testing levels (component, sub-assembly) and the correlation between experimental results and finite element simulations. Validity is strong within the context of helicopter crashworthiness simulation, as the design goals were met and validated.

Think critically

How might the choice of foam density or fabric weave affect the energy absorption characteristics of this design, and what trade-offs would these variations introduce?

Design Principles

"Optimized material and geometric configurations can be leveraged to control and mitigate impact forces within defined parameters."

This research highlights the effectiveness of specific material combinations and geometric designs in managing impact forces. It provides valuable data for engineers developing safety systems in transportation and aerospace, demonstrating a practical application of advanced materials for energy absorption.

What This Means for Your Design

Researchers created a special sandwich structure with foam and strong fabric that, when tested and simulated, showed it could absorb a crash's force well enough to keep the shaking within a safe range for a helicopter.

How to use in your project

1.Reference this study when exploring material science for impact resistance or when using simulation to validate design choices in your own design project.

Add to My Project

Quick Cite

Paragraph starter

The development of specialized energy-absorbing structures, such as the sinusoidal foam sandwich examined by Jackson et al. (2015), demonstrates the critical role of material science and geometric design in mitigating impact forces. Their work, which combined experimental testing with finite element analysis, successfully validated a design capable of achieving targeted acceleration reductions, offering a precedent for engineers seeking to enhance safety in high-impact scenarios.

Source

NASA STI Repository (National Aeronautics and Space Administration)

Impact Testing and Simulation of a Sinusoid Foam Sandwich Energy Absorber

journal · 2015

View source

Questions About This Research

What does the research say about sinusoidal foam sandwich design achieves targeted g-force reduction in crash simulation?: When designing for impact absorption, consider the synergistic effects of material properties, geometric form, and validated simulation models to achieve targeted performance metrics. Evidence: NASA STI Repository (National Aeronautics and Space Administration) (2015).
Why does "Sinusoidal Foam Sandwich Design Achieves Targeted G-Force Reduction in Crash Simulation" matter for design?: This research highlights the effectiveness of specific material combinations and geometric designs in managing impact forces. It provides valuable data for engineers developing safety systems in transportation and aerospace, demonstrating a practical application of advanced materials for energy absorption.
How can designers apply this research?: When designing for impact absorption, consider the synergistic effects of material properties, geometric form, and validated simulation models to achieve targeted performance metrics.
What were the main findings?: The sinusoidal foam sandwich energy absorber met the design goal of achieving average floor-level accelerations between 25- and 40-g.. Finite element simulations closely matched experimental results for load-displacement, acceleration-time history, and structural deformation.. The design demonstrated effective energy absorption and controlled deformation under impact loading.
What research method was used?: Experimental testing and finite element simulation.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2015 journal from NASA STI Repository (National Aeronautics and Space Administration).
What should I do differently in my next project?: When designing protective structures or impact mitigation systems, explore composite materials and geometric optimizations, validating designs with both physical testing and computational simulations.
What are the limitations?: The study focused on a specific helicopter airframe and crash scenario; performance may vary in different applications or impact conditions. The ELFOAM P200 foam's properties might be specific to the tested density.