SIST EN 3745-513:2006

Overview

SIST EN 3745-513:2006 is a European standard developed by CEN and the European Association of Aerospace Manufacturers (AECMA-STAN) that specifies a test method to evaluate the crush resistance of optical fibre cables used in aircraft. The standard defines how to determine an optical fibre cable's ability to withstand crushing forces under specified environmental conditions. This ensures that optical cables in aerospace applications maintain their performance and reliability despite mechanical stresses experienced during operation.

This standard is critical for manufacturers, quality control engineers, and aerospace system designers working with optical fibre cables in aircraft environments. It helps ensure compliance with stringent aerospace requirements by providing a uniform testing procedure.

Key Topics

• Scope: The standard focuses exclusively on the crush resistance test of optical fibre cables designed for aircraft use.
• Specimen Preparation: Cables must be stabilized under standard environmental conditions (temperature, humidity) before testing, typically for 24 hours.
• Test Conditions: Includes defining precise test parameters such as temperature, humidity, number and length of specimens, applied compressive force, duration of load, and any mandrel diameter usage.
• Test Apparatus: A specialized crushing device applies uniform pressure to fiber optic cable specimens. The apparatus consists of a flat steel base plate and a movable steel plate or mandrel to apply force over a 100 mm length of the cable. Plates are radiused to avoid damage from sharp edges.
• Measurement Methods: Continuous monitoring of attenuation variation during the test using Light Launch System (LLS) and Light Detector System (LDS) per EN 2591-100 and attenuation method C as defined in EN 3745-301.
• Test Procedure:
  • Measure reference power with no load.
  • Gradually apply the specified compressive force.
  • Maintain the load for a preset time duration.
  • Measure attenuation during load and after load removal post a 15-minute recovery.
• Post-Test Evaluations: Visual examination as per EN 3745-201 and attenuation measurement to ensure the changes remain within acceptable limits.
• Normative References: The standard references critical documents like EN 2591-100, EN 3745-100, EN 3745-201, and EN 3745-301 which govern general test methods, visual examination, and attenuation measurement.

Applications

• Aerospace Industry: Ensures optical fibre cables used in aircraft wiring harnesses meet durability requirements against compressive mechanical forces during flight and maintenance.
• Quality Assurance: Enables aerospace manufacturers and suppliers to validate cable robustness, ensuring communication and data transmission reliability.
• Cable Design Validation: Helps designers assess mechanical protection needs and optimize cable construction to enhance crush resistance.
• Regulatory Compliance: Supports compliance with aerospace standards and national regulations by providing a standardized test recognized across multiple European countries.
• Research & Development: Facilitates material testing and improvement by quantifying cable performance under crushing stresses.

Related Standards

• EN 3745-100: General test methods for aerospace optical fibre cables, defining environmental conditions and specimen preparation.
• EN 3745-201: Visual examination methods to detect cable defects post testing.
• EN 3745-301: Methods for measuring optical attenuation changes in aerospace fiber optic cables.
• EN 2591-100: Defines the Light Launch System and Light Detector System equipment used in optical testing.

SIST EN 3745-513:2006 provides a comprehensive and standardized methodology to assess and ensure the mechanical reliability of optical fibre cables under crushing forces in aerospace applications. Its adoption supports the aerospace industry's stringent quality demands for optical communications infrastructure, enhancing safety and operational integrity of modern aircraft systems.