Search Results

There are established federal requirements and industry standards for frontal crash testing of motor vehicles. Consistently applied methods support reliability, repeatability, and comparability of performance metrics between tests and platforms. However, real world collisions are rarely identical to standard test protocols. This study examined the effects of occupant anthropometry and passive restraint deployment timing on occupant kinematics and biomechanical loading in a moderate-severity (approximately 30 kph delta-V) offset frontal crash scenario. An offset, front-to-rear vehicle-to-vehicle crash test was performed, and the dynamics of the vehicle experiencing the frontal collision were replicated in a series of three sled tests. Crash test and sled test vehicle kinematics were comparable. A standard or reduced-weight 50th percentile male Hybrid III ATD (H3-50M) or a standard 5th percentile female Hybrid III ATD (H3-5F) was belted in the driver’s seating position.

Airbag and seat belt pretensioner deployment characteristics depend on multiple factors, such as the magnitude, direction, and rate of vehicle deceleration as detected by vehicle crash sensors and evaluated by vehicle-specific algorithms. Frontal airbag and pretensioner deployments are likely to be commanded during frontal crash events with high initial vehicle deceleration typically associated with high vehicle change in velocity (delta-V). However, within a range of moderate changes in vehicle speeds, referred to as the “gray zone,” a vehicle-specific algorithm may or may not command deployment depending on crash pulse parameters and occupant sensing, among other items. Publicly available testing in the moderate-speed range is lacking and would be useful to evaluate the effects of airbag and pretensioner deployment on occupant kinematics and loading.

A substantial percentage of serious and fatal injuries sustained by motor vehicle occupants occur in lateral impact collisions, and approximately one third of these injuries involve a far-side occupant. A center airbag, deploying inboard of the front seat occupants, has been integrated into certain vehicles to reduce far-side occupant excursion, to limit occupant interactions with the vehicle interior and/or another occupant, and to reduce occupant loading and injury potential. A series of sled tests was conducted to better understand the efficacy and limitations of a center airbag under a variety of high-speed lateral impact conditions in an environment outside of the production design. A production-level driver’s seat equipped with a seat-mounted center airbag was installed onto an open-air sled. A 50th percentile male SID H-3 was placed in the seat and restrained by a three-point seat belt equipped with retractor and buckle pretensioners.

A significant portion of real-world passenger vehicle side impacts occur at lower speeds than testing conducted by the National Highway Traffic Safety Administration (NHTSA) or the Insurance Institute for Highway Safety (IIHS). Test data from low- to moderate-speed side impacts involving late-model passenger vehicles is limited, making the evaluation of vehicle impact response, occupant loading, and injury potential challenging. This study provides the results of low- to moderate-speed impact testing involving a late-model mid-size sedan. Two full-scale Non-Deformable Moving Barrier (NDMB) side impact crash tests were conducted at speeds of 6.2 mph (10.0 kph) and 13.4 mph (21.6 kph). Instrumentation on the late-model sedan used for the test series included tri-axis accelerometers and seat belt load cells.

A significant number of vehicle-to-vehicle collisions involve front-to-rear impacts at low- to moderate-speeds. While a variety of studies have been conducted since the 1990s involving fore-aft collisions, those discussing the response of late model passenger vehicles during progressively more severe impacts are limited. In this study, four inline, front-rear tests were conducted using two midsize sedans of the same make, model, and year. An instrumented Hybrid III 50th percentile-male Anthropomorphic Test Device (ATD) was located in the driver seat of each sedan and was restrained using the standard three-point seat belt system. Instrumentation on the vehicles included tri-axis accelerometers and seat belt load cells. For each test, the centerlines of the vehicles were aligned, and the striking vehicle impacted the stationary target vehicle at closing speeds of 4.6, 7.9, 13.5, and 20.9 mph (7.4, 12.7, 21.7, and 33.6 kph).

Bollard systems are often used to separate errant vehicular travel from pedestrian and bicycle traffic. Various bollard systems are available for this function, including different installations, functional design, and protection levels. The security-type bollards are used primarily at high-security locations (e.g., military bases and other government installations) around the world. While a protocol exists for testing and rating security bollards, no such protocol or recommended practice or standard currently exists for non-security-type bollards. Non-security, concrete-filled bollards are commonly used by cities/states, local government organizations, and the private sector as “perceived impediments to access” to protect against slow-moving vehicles. There is a general lack of publically available test data to evaluate these non-security bollards and conventional installation procedures.

In reconstruction of on-roadway vehicle accidents, roadway surface gouges and the forces and energy attributed to the related vehicle components become important keys to resolving accurate accident reconstructions. Accounting for the forces applied to vehicle components and the energy dissipated from such forces can be helpful where supporting data exists. Roadway gouge forces vary depending upon such factors as road surface temperature and the velocity of the gouging mechanism. Other factors that may affect roadway gouges are road surface age, differing gouge tooth geometry, and road surface construction but these factors are not addressed in this paper. Calculation and summation of individual contact forces and contact energies can be significant in the accounting of accident vehicle motion reconstruction. This paper expands upon findings presented in SAE 2008-01-0173.

The BSAN crash pulse model has been shown to provide useful information for restraint sensing evaluation and for structural force-displacement studies in flat fixed rigid barrier (FFRB) crashes. This paper demonstrates a procedure by which the model may be extended for use with central and offset vehicle to vehicle (VTV) crashes through appropriate combinations of vehicle parameters.

In reconstruction of on-roadway vehicle accidents, tire-road surface friction coefficient, mu (μ), can be estimated using a variety of available data. Common ranges and values for μ are used in calculations forming the foundation for most accident reconstruction techniques. When the roadway surface is gouged or disrupted by vehicle components, accounting of dissipated energy can be successful where supporting force data exists. Roadway gouge forces can vary widely depending upon such factors as road surface construction, surface temperature, and the velocity and geometry of the gouging mechanism. Such dissipated energy can be significant in accounting of total reconstruction energy. This paper presents experiments aimed at quantifying gouge force by controlled pavement gouging tests.

Understanding of events within the history of a crash, and estimation of the severity of occupant interior collisions depend upon an accurate assessment of crash duration. Since this time duration is not measured independently in most crash test reports, it must usually be inferred from interpretations of acceleration data or from displacement data in high-speed film analysis. The significant physical effects related to the crash pulse are often essential in reconstruction analyses wherein the estimation of occupant interior “second collision” or airbag sensing issues are at issue. A simple relation is presented and examined which allows approximation of the approach phase and separation phase kinematics, including restitution and pulse width. Building upon previous work, this relation allows straightforward interpretation of test data from related publicly available test reports.