Browse Topic: Impact tests
With new energy vehicles developing rapidly, battery safety, as an important part of the impact on the range of new energy vehicles and vehicle safety, has become the focus of attention. The battery pack protection plate is a core component to protect the battery, its performance needs not only impact resistance, but also lightweight, honeycomb sandwich structure with its excellent energy absorption characteristics and weight reduction performance by the battery pack protection plate performance research. At present, the core-to-face sheet interaction in conventional sandwich structures subjected to impact loads has not been fully elucidated, and the quantitative characterization of damage is insufficient, so this paper aims to optimize the lightweight impact-resistant structure by exploring the synergistic energy dissipation mechanism between the high-strength core material and the steel plate. The study combines theory and simulation, adopting ideal rigid-plastic film theory to establish a critical response model to predict the structural failure threshold, equivalent single-layer theory to simplify the analysis of plywood, and a stiffness matrix model to quantify the structural mechanical contribution of each layer. A two-material synergistic design framework is proposed by fully considering the material properties and adopting the corresponding intrinsic structure and failure criteria for different materials. Analysis reveals that geometric confinement is a key characteristic of the honeycomb sandwich panel’s response and a strain gradient driving mechanism at low impact resistance, and a new energy distribution paradigm is found through the analysis of the energy absorption ratio. The theoretical and simulation results are in great agreement with each other, which just has a difference of 0.7% in the peak force, 1.4% in the critical displacement error, and less than 2% in the impulse integration error. The proposed dual-material co-design framework provides a solution for electric vehicle battery protection systems that balances lightweight and impact resistance.
The bird strike performance of the flight critical components of a rotorcraft is to be proved. The study investigates the bird strike performance of the cowling structure through experiments and simulations by considering a Building Block Approach. Based on this approach, bird impact tests on a rigid plate and composite panels are performed to validate Smoothed Particle Hydrodynamics method (SPH) bird model and composite material model in LS-DYNA. The composite material properties are obtained from the coupon level test results. After the composite material model is calibrated and validated, the bird strike performance of the cowling structure at critical locations is assessed. A good correlation between the experimental and numerical results was obtained at coupon, sub-component and component levels. The developed composite material modeling technique and validated bird models may be used in showing bird resistances of other airframe components of similar structure of the rotorcraft.
Electric vehicles (EVs) face unique safety challenges under pole side impact conditions, largely due to the presence of floor-mounted battery packs. Existing regulatory test procedures, such as FMVSS 214, primarily address occupant injury using full-height cylindrical obstacles. These procedures were originally developed for internal combustion vehicles (ICVs). However, real-world roadside crashes frequently involve obstacles of varying heights, such as guardrails, curbs, and median bases. While these obstacles pose limited risk to the passenger compartment, they can intrude into the battery pack and trigger thermal runaway. This study investigates the influence of obstacle height on EV pole side impacts. Finite element simulations of a commercially available sedan were conducted against rigid obstacles of different heights. Results reveal a non-monotonic trend of battery intrusion governed by the interplay between rollover dynamics and structural stiffness. Theoretical analyses were conducted to clarify the underlying mechanisms. When the obstacle height falls below the window frame level, rollover effects become more significant. The longer roll moment arm allows part of the impact energy to be dissipated through vehicle roll motion, leading to a reduction in battery intrusion. However, as the obstacle height is further reduced into the threshold beam and battery side beam region, the supporting structural members are bypassed. The equivalent contact stiffness drops sharply, resulting in significant battery intrusion. The findings demonstrate that obstacle height governs EV battery safety through a competition between rollover energy dissipation and reduced contact stiffness. This work provides new insights for extending existing side impact tests to low-height obstacles and offers guidance for vehicle safety design.
Automotive OEMs can derive significant cost savings by reducing the quantity of physical crash tests and thereby accelerate product development, when they follow the Euro NCAP Virtual Testing procedure. It helps in optimizing the overall vehicle development process via more efficient simulations, as well as facilitates in early adoption of new safety regulations. In this pursuit, companies must comply with strict Euro NCAP requirements, which includes transparency and traceability of virtual tests. A major challenge therein is model validation – which requires highly precise detailing and extensive use of data for accurately replicating real physics of the problem. Deploying these workflows into an existing simulation process can be a complicated and time-consuming task, particularly when integrating various simulation and testing methods. A powerful simulation process and data management system (SPDM) can thereby assist companies to automate their entire simulation process, ensures transparency for all stakeholders and optimizes the collaboration experience. In this paper, authors demonstrate how companies can use a SPDM system to integrate Virtual Testing into their simulation workflows, ensuring end-to-end automation, comprehensive documentation, data traceability and maximum transparency. Various aspects of Virtual Testing can be efficiently managed within SPDM system - definition and tracking of project requirements, efficient management of model data, automatic simulation setup, automated analysis of results and generation of interactive web reports consisting of Virtual Testing specific checks, which drastically reduces CAE engineer’s manual effort, followed by a secured and efficient transfer of data to Euro NCAP web portal. Ensuring input and output data against any manipulation is a key concern in an industrial level Virtual Testing process, which is addressed via automatic hash generation for the simulation data. The process of making data tamper proof can be managed and tracked within a SPDM system, which ensures confidence in simulation results.
Rear-facing infant seats that are positioned behind front outboard vehicle seats are at risk of being compromised by the rearward yielding of occupied front seat seatbacks during rear-impact collisions. This movement can cause the plastic shell of the infant seat to collapse and deform, increasing the risk of head injuries to the infant. Current designs of rear-facing infant seats typically do not consider the loading effects from the front seatback during rear-impact situations, which results in weak and collapsible shell structures. Moreover, regulatory compliance tests, such as FMVSS 213, do not include assessments of rear-facing infant seats under realistic rear-impact conditions. as the bench used for the regulatory test lacks realistic vehicle interior components. This study emphasizes the need for revised testing methodologies that employ sled tests with realistic seatback intrusion conditions to facilitate the development of improved infant seat designs. Research shows that rear-facing infant seats designed for real-world loading conditions can improve safety and injury outcomes for infants in severe rear-impact collisions in the presence of front-occupied seats.
Severe rear-impact collisions can cause significant intrusion into the occupant compartment when the structural integrity of the rear survival space is insufficient. Intrusion patterns are influenced by impact configuration—underride, in-line, or override—with underride collisions channeling forces below the beltline through the rear wheels as a primary load path. This force concentration rapidly propels the rear seat-pan forward, contacting the rearward-rotating front seatback. The resulting bottoming-out phenomenon produces a forward impulse that amplifies loading on the front occupant’s upper torso, increasing the risk of thoracic injury even when the head is properly supported by the head restraint. This study analyzes a real-world rear-impact collision that resulted in fatal thoracic injuries to the driver, attributed to the interaction between the driver’s seatback and the forward-moving rear seat pan. A vehicle-to-vehicle crash test was conducted to replicate similar intrusion characteristics and assess the relative kinematics between the seatback and rear seat structure. Results demonstrate that seatback bottoming out under intrusion conditions significantly elevates thoracic loading. These findings highlight the need for improved rear structural design strategies to manage load paths in underride scenarios and to minimize front seatback rearward collapse and associated occupant loading.
This study introduces a novel in-cabin health monitoring system leveraging Ultra-Wideband (UWB) radar technology for real-time, contactless detection of occupants' vital signs within automotive environments. By capturing micro-movements associated with cardiac and respiratory activities, the system enables continuous monitoring without physical contact, addressing the need for unobtrusive vehicle health assessment. The system architecture integrates edge computing capabilities within the vehicle's head unit, facilitating immediate data processing and reducing latency. Processed data is securely transmitted via HTTPS to a cloud-based backend through an API Gateway, which orchestrates data validation and routing to a machine learning pipeline. This pipeline employs supervised classifiers, Support Vector Machine (SVM), K-Nearest Neighbors (KNN), and Random Forest (RF) to analyze features such as temporal heartbeat variability, respiration rate stability, and heart rate. Empirical evaluations demonstrate the system's proficiency in classifying occupant states, including normal, distressed, and unconscious conditions, achieving high prediction accuracy with low false positive rates. Notably, the system attains sub-10-second detection latency and facilitates end-to-end response actions within a 5-minute window. Experimental deployment in a Mercedes vehicle demonstrated high accuracy in occupancy detection (97%), vital sign monitoring (94%), and full ERS (Emergency Response System) activation within five minutes, meeting Euro NCAP 2025+ Child Presence Detection (CPD) requirements. Furthermore, the cloud infrastructure supports the accumulation of health data, contributing to personalized driver profiles and informed decision-making for future interventions. This research underscores the potential of UWB radar technology in augmenting automotive safety through real-time health monitoring, paving the way for smarter and more secure vehicular environments.
Commercial vehicle sector (especially trucks) has a major role in economic growth of a nation. With improving infrastructure, increasing number of trucks on roads, accidents are also increasing. As per RASSI (Road Accident Sampling System India) FY2016-23 database, commercial vehicles are involved in 42% of total accidents on Indian roads. Involvement of trucks (N2 & N3) is over 25% of total accidents. Amongst all accident scenarios of N2 &N3, frontal impacts are the most frequent (26%) and causing severe occupant injuries. Today, truck safety development for frontal impact is based on passive safety regulations (viz. front pendulum – AIS029) and basic safety features like seatbelts. In any truck accident, it is challenging rather impossible to manage comprehensive safety only with passive safety systems due to size and weight. Accident prevention becomes imperative in truck safety development due to extremely high energy involved in front impact scenarios. The paper presents a unique safety development approach (for frontal impact safety development for N2 and N3 trucks) which enables smart synthesis of active and passive safety systems to comprehensively address real world safety. Four major areas are identified for truck safety development viz. structural crashworthiness, compatibility, occupant safety and ADAS (Advanced Driver Assistance System). The innovation lies in smart mix of these areas during product safety development. The study presents the safety development of light commercial vehicle (truck) with this approach. Structural crashworthiness & occupant safety are developed with extensive number of CAE simulations. Design is physically validated with frontal impact test. In addition, extensive mileage accumulation is generated across Indian roads to validate ADAS system performance.
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