Are GenX Civic bumpers capable of withstanding low-speed impacts without compromising the unit-body?

[250gtswb]

Are "5 mph" (or even "3 mph") bumpers entirely a thing of past at this point? Do our cars have hydraulic struts in between the bumpers (I mean the actual extruded-aluminum bumper bars, not the plastic bumper covers that we tend to call the bumpers) and the unit-body, or is that also a thing of the past? Do our cars even have styrofoam blocks between the aluminum bumpers and the bumper covers, the way my 2007 Si did? I'm asking because I'm curious to know to what extent the front bumper on a GenX Civic can absorb the energy of a low-speed impact without distorting the car's "frame" (unit-body / monocoque) even a little bit. While parking my '17 Si coupe today in a friend's cramped garage, my front bumper pushed up against an old wardrobe with enough force to deform the laminated particle-board door on the cabinet, but without causing any visible damage to my car. (This ended up being a favor for my friend, who hates that cabinet, but his wife has not allowed him to throw it out -- until now.)

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[zroger73]

Are "5 mph" (or even "3 mph") bumpers entirely a thing of past at this point? Do our cars have hydraulic struts in between the bumpers (I mean the actual extruded-aluminum bumper bars, not the plastic bumper covers that we tend to call the bumpers) and the unit-body, or is that also a thing of the past? Do our cars even have styrofoam blocks between the aluminum bumpers and the bumper covers, the way my 2007 Si did? I'm asking because I'm curious to know to what extent the front bumper on a GenX Civic can absorb the energy of a low-speed impact without distorting the car's "frame" (unit-body / monocoque) even a little bit. While parking my '17 Si coupe today in a friend's cramped garage, my front bumper pushed up against an old wardrobe with enough force to deform the laminated particle-board door on the cabinet, but without causing any visible damage to my car. (This ended up being a favor for my friend, who hates that cabinet, but his wife has not allowed him to throw it out -- until now.)

https://one.nhtsa.gov/cars/problems/studies/bumper/index.html

https://rts.i-car.com/images/pdf/oem-info/honda/body-repair-news/22196.pdf

http://hondapartsnetwork.com/part/9800087/Honda-Part-71130-TGG-A00-Front-Beam-Comp

 

[250gtswb]

https://one.nhtsa.gov/cars/problems/studies/bumper/index.html

https://rts.i-car.com/images/pdf/oem-info/honda/body-repair-news/22196.pdf

http://hondapartsnetwork.com/part/9800087/Honda-Part-71130-TGG-A00-Front-Beam-Comp

Thanks for those links! The images of the unibody of the GenX Civic show that the aluminum bumper beam is fixed, via aluminum mounting blocks, directly to the forward frame rails. No moving parts. I assume that a solid mounting like this means the energy of an impact is expected to be absorbed by the deformation of the bumper bar itself, or by some dislocation of the mounts. The old 5 mph bumpers relied on hydraulic struts to absorb the energy of impacts. I'm wondering, with our cars, whether mild impacts to the front or rear -- with insufficient energy to deform the extruded aluminum bumper beam -- simply transmit energy to the unibody, and whether this could have any negative effects (loosening of welds, small local distortions of the unibody, tiny changes in geometry of the subframe mounting points, work hardening and embrittlement of the structural steel, etc.).

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