Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor)

This standard specifies how the resistance to crack propagation of rigid transparent sheet is to be determined.

Luft- und Raumfahrt - Prüfverfahren für transparente Werkstoffe zur Verglasung von Luftfahrzeugen - Teil 21: Bestimmung des Rißfortpflanzungswiderstandes (K-Faktor)

Série aérospatiale - Méthode d'essais pour matériaux transparents pour vitrages aéronautiques - Partie 21: Détermination de la résistance à la propagation des criques (Facteur K)

Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor)

General Information

Status
Published
Publication Date
19-Mar-1989
Withdrawal Date
19-Sep-1989
ICS
49.045 - Structure and structure elements
Technical Committee
ASD-STAN - Aerospace
Drafting Committee
ASD-STAN/D 4 - Metallic
Current Stage
9093 - Decision to confirm - Review Enquiry
Start Date
21-Jan-2025
Completion Date
14-May-2025
Ref Project
SIST EN 2155-21:2001 - Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor)

Overview

EN 2155-21:1989 - part of the Aerospace series published by CEN - specifies a standardized test method for determining the resistance to crack propagation (K factor) of rigid transparent sheet materials used in aircraft glazing. The standard defines the scope and required procedures to assess how transparent glazing materials behave when cracks develop and propagate, providing consistent data for design, certification and quality control of aircraft windscreens, canopies and other transparent structural elements.

Key Topics

  • Scope and material applicability: Defines the types of rigid transparent materials for aircraft glazing covered by the method and the intended measurement objective (resistance to crack propagation).
  • Test principles: Establishes the conceptual approach for initiating and propagating cracks and for quantifying the material’s resistance using the K factor metric.
  • Specimen handling and preparation: Requirements for preparing representative samples and maintaining material integrity prior to testing.
  • Test conditions: Description of controlled environmental and mechanical test conditions required to obtain reproducible results (temperature, humidity, loading conditions).
  • Measurement and data recording: Guidance on measuring crack growth, determining the K factor, and recording relevant test data and observations.
  • Reporting requirements: Required test report content to ensure traceability and comparability (material identification, test parameters, results and any deviations).

Applications

EN 2155-21 is primarily used by:

  • Aerospace materials engineers and designers evaluating glazing materials for structural performance and safety.
  • Test laboratories performing accredited material property tests for aircraft components.
  • Aircraft OEMs and glazing suppliers for product development, quality control and material acceptance.
  • Certification authorities and safety assessors requiring standardized evidence of glazing durability and fracture behavior.

Practical uses include selection of glazing materials, verification of crack-arresting performance, comparative assessment of candidate sheets, and supplying consistent test evidence for design validation and regulatory review.

Related Standards

  • This publication is adopted nationally as SIST EN 2155-21:2001 (Slovenian identical version).
  • EN 2155-21 sits within the broader Aerospace test-methods series for transparent materials; users commonly reference adjacent parts of the EN 2155 series and relevant aerospace material and glazing standards when performing comprehensive evaluations.

Keywords: EN 2155-21, aerospace glazing, crack propagation, K factor, transparent materials, aircraft glazing test methods, resistance to crack propagation.

Frequently Asked Questions

EN 2155-21:1989 is a standard published by the European Committee for Standardization (CEN). Its full title is "Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor)". This standard covers: This standard specifies how the resistance to crack propagation of rigid transparent sheet is to be determined.

This standard specifies how the resistance to crack propagation of rigid transparent sheet is to be determined.

EN 2155-21:1989 is classified under the following ICS (International Classification for Standards) categories: 49.045 - Structure and structure elements. The ICS classification helps identify the subject area and facilitates finding related standards.

You can purchase EN 2155-21:1989 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CEN standards.

Standards Content (Sample)


2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor)Luft- und Raumfahrt - Prüfverfahren für transparente Werkstoffe zur Verglasung von Luftfahrzeugen - Teil 21: Bestimmung des Rißfortpflanzungswiderstandes (K-Faktor)Série aérospatiale - Méthode d'essais pour matériaux transparents pour vitrages aéronautiques - Partie 21: Détermination de la résistance a la propagation des criqu
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