![]() As you could see that in relatively shallow depth beam the distance between the neutral axis and tensile reinforcement is small and the main steel present can control tensile strains. In the above figure the area of the beam shaded in red is having tensile strain more than cracking strain of concrete. Tensile strains above the reinforcement are not substantial and thus there additional reinforcement is not essential. In relatively shallow depth members, the tensile cracks usually develop at the tensile most fiber and propagate towards the neutral axis. The intent of providing side face reinforcement is to control the crack width in tensile zone of concrete.Īs per the design philosophy considering a balanced section the member is designed such that concrete reaches compressive strain of 0.0035 when steel reaches tensile strain of 0.002+0.87fy/Es.We provide reinforcement wherever cracks are expected to occur.Concrete cracks when tensile strain exceeds.In determining the front quarter of the vehicle length we need to know what is included in the measurement.Įxample would be if the bumper guards on the front bumper are included in the measurement.Īlthough the vehicle we receive from the manufacturer as a completed vehicle is not certified as a forward control, if we add a step either permanent or fold-up behind the original rear bumper, can this increase in length dimension be used to determine the front quarter of the vehicle? The purpose of this letter is to request interpretation relating to the NHTSA definition of "forward control." ![]() Office of Chief Counsel National Highway Traffic Safety Administration SHELLER-GLOBE CORPORATION Vehicle Planning and Development Center ![]() If you have any further questions, please let me know. The notice also states the agency's intention to eliminate the forward control exemption found in other Federal motor vehicle safety standards. 201, 203 and 204 to forward control vehicles. I have enclosed for your information a notice of proposed rule-making which would extend Standards No. Therefore, the agency will not consider a permanent or fold-down step as a part of the bumper face bar for the purposes of determining vehicle length. Components such as a permanent or fold-down step which are not associated with the bumper system's function are not considered part of the bumper face bar for the purposes of Part 581 Bumper Standard (43 F.R. For the purposes of determining vehicle length, the agency will consider bumper guards as a part of the vehicle bumper face bar and thus included in the measurement of vehicle length. In the context of the Part 581 Bumper Standard (49 CFR 581), the agency considers bumper guards to be part of the bumper face bar if they are contacted by the impact ridge of the pendulum test device used in compliance testing (43 F.R. Overall vehicle length should be determined by measuring the maximum longitudinal distance between the foremost point on the front bumper face bar and the rearmost point on the rear bumper face bar. Your specific concern is how to measure a vehicle's length to determine if "the steering wheel hub is in the forward quarter of the vehicle length." TEXT: This is in response to your letter of February 15, 1979, concerning the definition of "forward control" vehicle contained in 49 CFR 571.3. ![]() FROM: AUTHOR UNAVAILABLE Frank Berndt NHTSA ![]()
0 Comments
Leave a Reply. |