ASME RT-2:2021 pdf download

ASME RT-2:2021 pdf download.Safety Standard for Structural Requirements for Heavy Rail Transit Vehicles
1 SCOPE
The objectives of the passive safety requirements described in this Standard are to reduce the risk to passenger injury and damage to equipment resulting from collision accidents by providing a means of protec- tion when all possibilities ofpreventing an accident have failed. In the event ofa collision, application ofthis Stan- dardprovides protectionforthe occupants ofnewdesigns ofcrashworthyvehiclesthroughthepreservationofstruc- tural integrity, reducingthe riskofoverridingand limiting decelerations. This Standarddoes notextendto the design of the vehicle interior structures that may help reduce injury risk caused by impacts between the occupants and vehicle interior, beyond limiting vehicle acceleration and consequential secondary impact velocity of passen- gers colliding with interior surfaces.
2 DEFINITIONS
This Standard relies, where practical, on terms already inusebyASME, the AmericanPublicTransportationAsso- ciation (APTA), and the Institute ofElectrical and Electro- nics Engineers (IEEE). For the purposes ofthis Standard, the following definitions apply:anticlimber: a structural memberormechanism located at each end of the vehicle, used to engage an opposing vehicle, coupled or not, to resist relative vertical travel between the two carbodies during a collision. antitelescoping plate: a single structural member that spans the full width of the carbody at the top of the end frame, that is attached to the tops of the collision and corner posts, and is designed to transmitthe collision and corner post top reaction loads to the carbody sides. articulation: a rotating connection at the intermediate ends of carbody sections to allow negotiation of tracks with various vertical and horizontal profiles. average collision acceleration: the longitudinal accelera- tion of each car computed using a 100-ms simple moving average over the duration of the collision event and averaged over each car. belt rail: a longitudinal structural member ofthe carbody located on each side of the carbody below the passenger side windows. The distance between opposite belt rails often establishes the overall width of the carbody, exclu- siveofthesidedoorthresholds,sidecameras,andmirrors. car: see heavy rail transit vehicle. carbody: the main load-carrying structure above all truck suspension units. It includes all components that are connected to this structure and contribute directly to its strength, stiffness, and stability.collision posts: a set of two full-height structural posts located at each end of the carbody, extending from the bottom of the underframe structure up to a structural shelf or an antitelescoping plate. Collision posts may be made of several structural members assembled to each other, provided that the required performance is met. They are located at the approximate one-third points across the width of the vehicle, and are forward of the seating position of any passenger or crew person. An alternative to collision posts is a collision wall. collision wall: a structure at the leading end ofthe vehicle spanning the area between the structural shelf, corner posts, and top of the underframe. The use of a collision wallisintendedtoprovideacollisionperformanceequiva- lent to a collision post design. consist: a set of vehicles forming a complete train.corner posts: a set of two full-height structural posts located at the outside corners of the passenger compart- ment or at the extreme corners ofthe carbody,coupler system: a system comprised of the coupler head, drawbar, draft gear, and attachments to the carbody, permitting the connection between vehicles or trains. crash energy management(CEM): a method ofdesign and manufacture of vehicles that enhances crashworthiness by assigning certain structural members or components of the carbody and the coupler system the task of absorbing a portion ofthe collision energy in a controlled manner (see energy absorption zone).