In a densely populated urban environment, errant vehicles may pose a serious threat to neighboring traffic of pedestrians, bicyclists, and even to their drivers. Preliminary studies have indicated that street curbs do not offer any meaningful protection against errant vehicles, which can easily traverse street curbs even at small velocity and shallow angle. The paper presents research results of a study, in which computational mechanics was utilized to predict vehicle trajectories upon traversing standard Florida DOT street curbs. Computational analysis was performed using LS-DYNA computer code and two public domain, finite element models of motor vehicles: Ford Festiva and Ford Taurus. The suspension systems of original vehicle models were evaluated and additional, required suspension components were identified and developed. The finite element models of the required suspension systems were created using geometry from the actual suspension parts, captured using a digitizing arm. Due to complex geometry of these parts, the MSC-PATRAN preprocessor was used to create data for LS-DYNA code. Shock absorbers were modeled using discrete spring and damper elements. Connections for the modified suspension systems were carefully designed to assure proper range of motion for the suspension models. Inertia properties of the actual vehicles were collected using tilt-table tests and they were used for LS-DYNA vehicle models. A standard FDOT street curb model was developed using a combination of rigid walls and shell elements. Initial trajectory analyses were performed for two vehicle models using the non-linear, finite element code LS-DYNA. An explicit, finite difference algorithm implemented in LS-DYNA was used to carry out the dynamic analysis in time domain. Initial, computational mechanics analyses suggest that vehicles tend to retain larger amount of their kinetic energy after traversing street curbs. It is therefore dangerous to consider street curbs as functioning similarly to guardrails. Smaller vehicles, impacting street curbs at shallow angles, appear to be also dangerous.
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