BS EN 13749-2021 pdf free download.Railway applications — Wheelsets and bogies — Method of specifying the structural requirements of bogie frames.
4 Technical specification
4.1 Scope The technical specification shall consist of all the information describing the functional requirements of the bogie frame and the interfaces with associated components and assemblies. It shall also comprise, as a minimum, the general requirements of use, the conditions associated with the vehicle equipped with the bogies, the operating characteristics, the conditions associated with maintenance and any other particular requirements. The technical specification shall also identify all appropriate mandatory regulations and define the parts of the validation and acceptance procedure (Clause 6) and the quality requirements (Clause 7), which are specifically required, and the way in which evidence to show that the requirements have been met is to be provided. NOTE If the customer is unable to define the technical specification completely the supplier may propose a technical specification and submit it to the customer (and the approval authority where relevant) for agreement.
4.2 General requirements
The technical specification shall indicate the type of bogie required in terms of its use. It shall also indicate the intended life of the bogie, its average annual distance run and its total distance run and all the information that is applicable to a bogie frame associated with the Essential Requirements of a TSI as indicated in EN 15827. Information that is particularly relevant to bogie frame design is indicated in the following clauses.
4.3 Design load cases
The technical specification for the bogie frame shall consist primarily of the load cases required for the design of the bogie as specified in EN 15827, plus any additional load cases required by that standard or arising from the application.
The load cases shall be based on the vehicle mass states given in EN 15663. However, for some applications and fatigue assessment methods it will be necessary to use additional vehicle loading conditions (expressed as functions of the cases in EN 15663) to obtain an accurate description of the vehicle payload spectrum for design purposes. The development of the design load cases is discussed in Annex B and examples of design load cases associated with bogie running and due to the attachment of equipment are given in Annexes C and D respectively.
NOTE If it is proposed to use the endurance limit approach to fatigue strength assessment the data on the number of events is not required and only the extreme repetitive load conditions need to be defined. 4.4 Vehicle conditions and interfaces The technical specification shall also include the following information from the requirements of EN 15827 interpreted for applicability to the bogie frame:
vehicle body interfaces and clearances;
gauge reference profile and bogie movement envelope;
suspension geometry and attachments;
interfaces to traction and braking systems and all other attached equipment;
electrical and pneumatic system connections;
environmental requirements;
maintenance requirements.
4.5 Particular requirements
The technical specification shall indicate any particular requirements related to the bogie frame that are not covered by the above clauses, for example, operating conditions, materials, types of construction and methods of assembly (e.g. treatment of welds, shot peening). 5 Verification of the design data All necessary means (e.g. analysis, drawings, tests) shall be used to carry out the design.
The information supporting the design of the bogie frame shall be verified by the documents defined in the technical specification and those required by applicable standards and regulations which permit:
the bogie frames to be designed and manufactured in accordance with the requirements of the technical specification, EN 15827 and this European Standard;
all the checks considered necessary for the validation and acceptance to be carried out.
6 Validation and acceptance of the design
6.1 General The aim of the validation plan is to prove that the design of the bogie frame fulfils the conditions defined in the technical specification. In addition, it shall show that the behaviour of the bogie frame, constructed according to the design, will give satisfactory service without the occurrence of defects such as catastrophic rupture, permanent deformation and fatigue cracks. It shall further demonstrate that there is no adverse influence on the associated bogie components or sub-assemblies.
The validation plan shall be compatible with that for the bogie as a whole as specified in EN 15827 and in particular the requirements of the following clauses of this European Standard. Acceptance of the product will normally be dependent on a satisfactory completion of the validation plan but may contain other conditions outside the scope of this European Standard. The technical specification shall include guidance on how the bogie design is to be validated (including conformance with any applicable regulations) and shall state all the parameters that are necessary for the application of the different parts of the procedure. These parameters shall be defined in three stages:
the validation plan (e.g. combination of load cases for analysis and static tests, programmes for fatigue tests, routes for track tests);
the values of the different load cases;
the acceptance criteria (treatment of measured or calculated values, limiting stresses, criteria for completion of fatigue tests, etc.).
6.2 defines which parts of the validation plan should be included in any particular case.
NOTE In order that the acceptance procedure is completely defined, the supplier should identify the methods of demonstrating conformance to the requirements if they are not incorporated into the technical specification.BS EN 13749 pdf download.