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ASME RT-1-2009 pdf download

ASME RT-1-2009 pdf download.Safety Standard for Structural Requirements for Light Rail Vehicles.
(b) minimize the loss of occupant volume resulting from structural collapse or structural penetration (c) provide for a progressive controlled collapse of energy absorption zones of the carbody structure while limiting the average longitudinal acceleration Structural energy absorption zones shall be located at the ends of the carbody structure and shall be acti- vated prior to crush of other carbody structures, follow- ing the sequence and magnitude of collapse as specified in Table 2. Table 2 further specifies required strengths for structural elements such as collision posts and corner posts, to protect passengers and operators from struc- tural penetration and loss of occupant volume in the event of a collision with another vehicle or obstruction. Other requirements in Table 2 specify design criteria for vehicle anticlimbing protection in vehicle-to-vehicle collisions. The controlled collapse displacement of the energy- absorbing zones shall be as specified in Tables 1 and 2. Collapse shall not commence until the end sill compres- sion load identified in Item 2 of Tables 1 and 2 has been exceeded. The end sill compression is the minimum allowable value for the initiation of crushing, with the exception of the energy absorption in Zone 1 in Tables 1 and 2. The design end-sill compression load shall be selected based on the CEM and collision survivability plan per section 8.
(1) Zone 1. The first zone is designed to absorb impact energy in the event of a relatively low-severity frontal collision with another LRV or streetcar. This energy absorption zone can be designed with a replace- able or recoverable element. (2) Zone 2. This zone is to be designed to accommo- date collisionsbetweentwo single like LRVsorstreetcars with a closing speed of 24 km/h (15 mph). Crush shall be limited to the vehicle forward cab section. There shall be no loss of survivable volume in the passenger com- partment. Proper functioning of this zone requires the engagement of both LRV and streetcar anticlimbers to prevent telescoping of the vehicles. (3) Zone 3 (Applicable to Light Rail Vehicles Only). Having consumed the energy in Zones 1 and 2, this zone is intended for higher speed to absorb the additional energy associated with collisions between two single like LRVs at a closing speed of 40 km/h (25 mph). The crush damage in this zone shall be limited to the front cab sections ofbothcollidingvehicles. Inelastic deforma- tions in the passenger compartment are only allowable if a survivable volume is maintained. After all the energy absorption capability in the three zones has been exhausted in a collision, the crush behav- ior of the vehicle shall continue to occur in a controlled manner progressing from the cab end in a rearward direction. The operator’s cab door and seat shall be designed to allow quick emergency egress of the operator into the occupant compartment. Armrests on the operator’s seat shall fold back or be easily moveable to permit easy egress and the cab-to-passenger compartment door shall open outward from the cab. 5.2 Jacking and Torsional Loads The loading conditions and the margins of safety of stresses below yield strength shall be specified. 6 COUPLER SYSTEM 6.1 Characteristics The coupler system, including drawbars, draft gear, and attachments to the carbody, shall respond to normal and overload conditions in a predictable manner.
7.1 Austenitic Stainless Steel Structural use of austenitic stainless steel shall be in accordance with APTA SS-C&S-004-98. 7.2 Low Alloy High Tensile Steel Structural use of low alloy high tensile (LAHT) steel shall be in accordance with the requirements of Section 4.2 of APTA SS-C&S-034-99. 7.3 Aluminum Structuraluse ofaluminumandaluminumalloysshall be in compliance with APTA SS-C&S-015-99. 7.4 Static Strength The limiting static material properties shall be as given in the referenced material standard. When other standards are used, the equivalency shall be demon- strated between these standards and the referenced material standards. 7.5 Nonmetallic Materials If nonmetallic materials are utilized, then this Stan- dard shall be applied to the extent possible. Data from internationally accepted standards that represent the performance of the material may be applied pending demonstration ofequivalency to a U.S. code or standard. 8 CRASH ENERGY MANAGEMENT (CEM) To improve crashworthiness, this Standard requires that the analytic and test principles ofcrash energy man- agement (CEM) be applied, including the use of analyti- cal tools to verify that the carbody design is stable and crushes as intended. Analysis for the purpose of evalua- tion of load cases specified in Items 17 through 19 of Table 1 or Items 17 and 18 of Table 2 shall be of the time-dependent, large-deflection type.

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