Roof Crush Analysis

One of the tests used in occupant safety analysis is a roof crush test.

Roof crush analysis.

A safer car does not deform as much providing the occupant a larger survival space during this kind of accident. Roof crush simulation federal motor vehicle safety standard no. Objective of the test roof crush is the failure and displacement of an automobile roof into the passenger compartment during a rollover accident. Used for quasi static roof crush analysis.

Roof crush and roll velocity loss are however largely independent of lateral velocity. A and b pillars tended to remain virtually straight. Material approach is preferred over the geometric approach due to space constraints in the passenger compartment as well as weight limitations. With the material and property cards assigned the free nodes and free masses as well as unattached springs and beams are removed from the model.

The recently released nhtsa study roof crush analysis using 1997 2001 nass case review which has been in the works for nearly four years reviewed nass rollover crashes in an effort to determine whether roof deformation patterns identified in an earlier agency study were still valid for current vehicle designs see upgraded rollover roof crush protection. Fig 16 swr versus platen displacement for honda accord and lwv in iihs roof crash test. The acceleration induced by the tripping motion itself may be sufficient to eject unbelted occupants before rollover habberstad 1986. Vehicle damage is mostly influenced by vertical velocity not roll rate or lateral velocity.

Structural analysis solutions for body chassis powertrain and component applications capabilities applications linear nonlinear dynamics durability test correlation composites component strength roof crush nvh part fatigue. The analysis procedure consisted of examining the case summary crash diagrams and photographic documentation to observe general roof damage patterns. It is used to evaluate how a car will deform during a rollover accident. Each case was evaluated against the deformation patterns observed from the previous analysis.

Rollover test and nass case analysis nhtsa june 1992. The relationship between injury levels and intrusion or roof crush has been statistically established but the mechanism has been thought sometimes to be somewhat obscure. The roof strength is measured by the resistance force required to push a rigid plate into the roof structures. The reason for such low roof crush resistance is the reduced model which does not include all of the components of the biw to offer proper geometric resistance to the impactor displacement.