IEC 60068-2-85:2019

Overview

IEC 60068-2-85:2019 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies environmental vibration testing through long time history replication. This method is designed to assess a specimen’s ability to withstand dynamic loads over an extended period without suffering unacceptable functional or structural degradation. The testing employs vibration signals defined by time histories, which are either recorded from real environments or artificially generated, allowing highly tailored vibration tests specific to particular applications.

By focusing on deterministic vibration inputs with potentially complex, transient or periodic characteristics, IEC 60068-2-85 provides a flexible and comprehensive approach well-suited for scenarios where conventional vibration tests such as sinusoidal or random vibration are insufficient. This standard is crucial in verifying the durability and reliability of components and equipment subjected to complex vibration environments.

Key Topics

• Long Time History Replication: Utilizes a detailed digital time history to replicate real or simulated vibration conditions over an extended timeframe, capturing transient and periodical vibrations.
• Deterministic Vibration Inputs: Contrasts with random or general shock tests by allowing vibration profiles that are precisely defined and controlled.
• Test Apparatus Requirements: Specifies the use of electrodynamic or servo-hydraulic vibration generators equipped with computer-based control systems capable of reproducing complex vibration time histories accurately.
• Functional and Structural Integrity: Focuses on evaluating specimens for both operational performance and physical degradation caused by dynamic loads.
• Engineering Judgement: Emphasizes the importance of expert specification and interpretation of test parameters, severity, duration, and analysis to align with the specimen’s real-world conditions.
• Pre- and Post-Test Performance Evaluation: Involves initial and final measurements to monitor changes in specimen behavior and integrity.
• Tailored Test Design: Enables testing tailored to unique application requirements that are not covered by other IEC vibration standards such as IEC 60068-2-27 (shock tests), IEC 60068-2-6 (sinusoidal vibration), or IEC 60068-2-81 (shock response spectrum).

Applications

IEC 60068-2-85:2019 is applied in industries and scenarios where equipment and components face complex vibration environments that cannot be effectively simulated by traditional test methods. Typical applications include:

• Aerospace and Transportation: Testing avionics, instruments, and vehicle components exposed to specific vibration profiles during operation, launch, or transport.
• Electronics: Assessing durability of sensitive electronic devices when subjected to vibrations with complex long-term histories.
• Defense and Military Equipment: Verifying performance under vibrational stresses reflecting field or transportation conditions.
• Industrial Machinery: Ensuring reliability of machinery and parts subject to operating vibrations beyond simple harmonic models.
• Custom Environmental Simulations: Creating unique vibration tests based on recorded real-life vibration or simulation data for novel or specialized products.

This standard supports test developers and quality engineers in designing vibration tests that mirror actual usage conditions closely, leading to improved confidence in product reliability and safety under dynamic loads.

Related Standards

IEC 60068-2-85 is part of the broader IEC 60068 series on environmental testing and complements several other vibration-related standards:

• IEC 60068-2-6: Specifies sinusoidal vibration testing commonly used for periodic vibration environments.
• IEC 60068-2-27: Defines shock tests with defined shock pulses for impact and transient conditions.
• IEC 60068-2-64: Covers random vibration testing with power spectral density controls.
• IEC 60068-2-81: Provides shock response spectrum methods useful for describing shock severity more generally.
• IEC 60068-3-8: Guidance for estimating dynamic vibration environments and selecting appropriate testing methods.

Understanding the relationship between these standards helps practitioners select the correct vibration test type based on specimen use case and vibration characteristics.

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