Whether it’s a satellite orbiting Earth, an aircraft cruising at high altitudes, or a spacecraft venturing into the depths of space, reliability is paramount – every component must endure extreme conditions without fail. This is where environmental testing comes into play, serving as a critical tool in ensuring the resilience and safety of aerospace technologies.
Understanding Stress Testing:
Stress testing involves subjecting materials, components, or systems to conditions that exceed their normal operating parameters under one or more stressing environments. These environments can include Thermal Cycling, Vibration, Electrical Stress, Thermal Shock, Humidity, and others.
The goal is to identify weaknesses, failure points, or performance limitations that may emerge under extreme circumstances. In aerospace, where the environment is inherently harsh and unforgiving, stress testing is indispensable.
One of the most common methods of stress testing is mechanical testing, which evaluates how materials respond to various loads, pressures, and vibrations. This includes tension, compression, bending, and torsion tests, simulating the forces experienced during launch, flight, and landing.
Environmental stress testing exposes aerospace components to extreme temperatures, humidity levels, and pressure conditions. These tests mimic the rigours of space travel, where temperatures can fluctuate dramatically, and vacuum environments prevail.
Fast Change Rate Temperature Testing:
Fast change rate temperature testing, a subset of environmental stress testing, focuses specifically on rapid temperature transitions. Aerospace systems must endure abrupt changes in temperature as they move between different environments, such as the frigid cold of space to the intense heat during re-entry.
This testing method involves swiftly altering temperatures within a controlled chamber, simulating the rapid thermal cycling experienced by aerospace components. By subjecting materials to these extreme conditions, engineers can assess their thermal stability, coefficient of thermal expansion, and overall performance under temperature stress.
Industry Standards
Stringent regulatory requirements also necessitate thorough testing and validation to ensure compliance with safety standards. Manufacturers in aerospace and defence industries rely on two primary standards to thoroughly evaluate the durability of components and materials subjected to varied environmental stresses.
DO-160, established by the Radio Technical Commission for Aeronautics (RTCA), offers a comprehensive framework for testing airborne equipment across 26 sections, covering factors like vibration, temperature, altitude, humidity, electrostatic discharge, and radio frequency susceptibility. This standard, notably revised in December 2010 as DO-160G, is internationally recognised and accepted by most global jurisdictions, ensuring the performance of aerospace systems.
Similarly, MIL-STD-810, a U.S. Military Standard dating back to 1962 and most recently updated in February 2019 as MIL-STD-810H, encompasses over 30 environmental testing methods. MIL-STD-810 provides guidance rather than prescription, requiring customised testing to assess materials and components’ resilience under anticipated environmental conditions. These standards play a crucial role in ensuring the reliability and safety of aerospace technologies, as manufacturers worldwide adhere to their rigorous testing protocols.
The aerospace industry constantly faces the challenge of pushing the boundaries of technology while maintaining safety and reliability standards. Stress testing and fast change rate temperature testing play a crucial role in this endeavour.
The ESPEC AR Series test chambers available in the UK through Unitemp, offer tailored solutions for aerospace stress testing and fast temperature change testing, facilitating the assessment of thermal stability, coefficient of thermal expansion, and overall performance of aerospace components under demanding conditions. With Unitemp’s expertise and ESPEC cutting-edge technology, aerospace manufacturers and suppliers can push more resilient technologies for the future of exploration and discovery. For more information see AR Series test chambers.
