Optimizing Car Front Bumper Design to Minimize Pedestrian Injuries

Posted by Faculty Of Automotive Engineering Technology at 03/08/2025

Pedestrian safety remains one of the most critical challenges in modern transportation engineering. While global road fatalities are gradually declining, the number of pedestrian deaths continues to rise. According to the U.S. Governors Highway Safety Association (GHSA), 7,508 pedestrians lost their lives in 2022 — the highest figure since 1981. Similarly, in Vietnam, over 9,000 people were killed and 11,000 injured in road accidents between 2022 and mid-2023.

Addressing this issue, researchers from Van Lang University and Ho Chi Minh City University of Technical Education conducted an in-depth study on the optimization of car front bumpers to minimize lower limb injuries in pedestrian collisions.

Key Research Objectives

The study aims to analyze and redesign the front bumper structure to absorb impact energy effectively during vehicle–pedestrian collisions. Specifically, it evaluates:

The geometry (profile) of the front bumper,
The material composition, and
The thickness optimization using advanced simulation tools such as HyperMesh and LS-DYNA.

Methodology

The research used the Toyota Camry finite element model and the V-THUMS pedestrian simulation model to replicate realistic collision conditions at 40 km/h. The study assessed several biomechanical injury indices — including bending moment, resultant force, and stress distribution — across the femur, tibia, and knee joints.

Three key factors were optimized:

Profile: Comparing original vs. two redesigned shapes.
Thickness: Testing levels of 2.0 mm, 2.5 mm, 3.0 mm, and 4.0 mm.
Material: Evaluating polymers (PC, PP-TD20, PCABS) and metals (A3003 aluminum, SAPH440 steel).

Findings

Simulation results revealed:

The Shape 2 bumper profile significantly reduced bending moments and resultant forces on pedestrians’ lower limbs.
An optimal thickness of 2.5 mm achieved the best balance between impact absorption and structural integrity.
Among materials tested, PP-TD20 plastic showed superior performance in reducing both bending and total forces while maintaining durability.

Impact Distribution

Comparative analysis of von-Mises stress distributions indicated that the optimized bumper reduced concentrated stress on the tibia region during collisions. Additionally, ligament rupture simulations demonstrated that the improved bumper design lowered the probability of knee ligament failures by 25–30%.

Figure 1: Basic structure of car front bumper

Conclusion

This research highlights the potential of finite element-based optimization in improving pedestrian safety. The optimized bumper design—featuring a 2.5 mm PP-TD20 structure—provides a viable approach to reducing leg injuries by over 20%, offering new design guidelines for automakers.

View more

Simulation Insights into Sedan Deformation and Passenger Safety in Multi-Vehicle Collisions
Following the numerical modeling in the first phase, this study presents an in-depth simulation analysis of a sedan’s structural response under rear-end chain collisions involving two heavy-duty trucks. The simulation aims to quantify how collision speed, energy distribution, and structural deformation interact to affect the safety of vehicle occupants.
Understanding Sedan Structural Behaviour in Multi-Vehicle Collisions Involving Heavy Trucks
Road safety remains a growing challenge in Southeast Asia, where high traffic density and mixed vehicle types increase the risk of severe multi-vehicle collisions. Among the most dangerous scenarios are chain crashes at intersections, where a heavy-duty truck loses braking control and collides with stationary vehicles waiting at traffic lights. This study, conducted by Van Lang University (Vietnam), Binh Duong Economics and Technology University (BETU), and Universiti Teknologi Malaysia (UTM), investigates the crashworthiness of sedan passenger vehicles under such multi-vehicle impacts, focusing on both front and rear-end deformation.
Finite Element Insights into Injury Severity and Design Optimization for Pedestrian Safety
Building on previous studies, this research investigates how vehicle design and anthropometric differences influence pedestrian lower-limb injuries during sedan collisions. By simulating crashes between three vehicle models (Taurus, Neon, Camry) and the Vietnamese-scaled V-THUMS pedestrian model, the team provides valuable engineering data to enhance vehicle front-end safety design.
Understanding Lower Limb Injuries of Vietnamese Pedestrians in Sedan Collisions
Pedestrian safety has become a critical public concern in Vietnam’s rapidly growing urban centers, where mixed traffic environments expose vulnerable road users to a high risk of accidents. According to international data, lower limb injuries account for the majority of pedestrian traumas in vehicle collisions, particularly with sedan-type vehicles. In response to this issue, researchers from Van Lang University and Ho Chi Minh City University of Technology and Education conducted a finite element simulation study to analyze the mechanism of pedestrian lower extremity injuries using the V-THUMS model—a human body model scaled to Vietnamese anthropometry.
Simulation-Based Study of Pedestrian Impact and Energy Absorption in Vehicle Bumpers
Pedestrian collisions with vehicles are a growing safety concern, especially in urban environments with high traffic density. Traditional vehicle bumpers are designed primarily for crash energy absorption between vehicles, not for minimizing pedestrian injuries. This limitation inspired a Vietnamese research team to apply simulation-based design and optimization to improve pedestrian safety performance.