【国外标准】 Standard Practice for Establishing the Minimum- and Maximum-Width Configurations for Crash Testing of Exceptionally Long Variable-Width Vehicle Barriers

5.1 Test Method F2656/F2656M states that variable-width barriers shall be tested in minimum- and maximum-width configurations. Interpolations between maximum and minimums are allowed if there are no structural modifications made to the barrier (that is, all structural components, including spacing of support members and connections, are similar between the two barriers tested at minimum and maximum widths). Extrapolation outside of the tested minimum- and maximum-width configurations is not allowed.5.2 However, there is a class of barriers such as some nets and fences that rely on a structurally repetitive interior system and strengthened end terminals or anchorages that are not explicitly treated under Test Method F2656/F2656M. There are situations where the interior system of the barrier could be exceptionally long and it is impractical or impossible to test the maximum-width configuration due to test facility site constraints, as an example.5.3 When a variable-width barrier is dependent on a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals, this practice shall be used to establish the maximum-width configuration that is equivalent to an infinitely long barrier.5.4 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Knowing the condition designation and penetration rating provides the ability to select an appropriate barrier for site-specific conditions around a facility.5.5 Use of this practice assumes:5.5.1 Except for the instrumented end terminations, the structurally repetitive interior system is constructed and installed in a manner that represents the proposed actual service installation;5.5.2 Except for the instrumented end terminations, the structurally repetitive interior system conforms to supplier specifications and drawings;5.5.3 The actual service installation of the structurally repetitive interior system shall be terminated using the strengthened end terminals used for the minimum-width configuration test; and5.5.4 The instrumented end terminations used for the maximum-width configuration shall provide axial load resistance only.1.1 This practice provides a procedure for applying Test Method F2656/F2656M test criteria to an exceptionally long (that is, 300 ft [91 m] or greater) variable-width vehicle barrier as defined by Test Method F2656/F2656M.1.2 This practice provides a procedure to establish a maximum-width configuration that is equivalent to an infinitely long barrier for a variable-width barrier as defined by Test Method F2656/F2656M.1.3 This practice applies only to variable-width barriers that are dependent on both a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals.1.4 This practice applies only when it is impractical or impossible to install the maximum-width test article of a variable-width barrier because the test facility site constraints limit the practical length of the test article.1.5 This practice does not apply when its use is employed solely with the intent of reducing the test article installation cost when it is practical to test the maximum-width installation length.1.6 This practice does not apply to continuous or other types of vehicle barriers.1.7 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Further, the complete variable-width barrier shall receive a single penetration rating that is determined as the maximum penetration rating for both the minimum- and maximum-width configurations tested, and is taken to be the final penetration rating. The penetration rating is not based on engineering calculation or judgment.1.8 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.