Environmental Simulation Testing: Staying Ahead of Trouble One Test at a Time
What is environmental simulation testing? Simply put, simulated test environments are all about preparing products for real-world use. This is accomplished by gaining as much testing experience and performance data as early as possible during the products’ lifecycles. Simulated environmental testing usually involves creating artificial environments for test items to determine their expected resilience to their anticipated environments.
A classic example of environmental simulation testing involves testing components for satellites. Components intended for use on satellites face recurring changes between temperature extremes several times per 24-hour period. When components are in direct sunlight, they may reach temperatures up to 120°C. When they are in the shadow, they may cool to temperatures of -100°C. A satellite which orbits the earth approximately 14 times per day will experience over 50,000 thermal cycles between these extremes in its lifetime! Cycling between extremes tends to change material properties and wear equipment out prematurely.
The components of satellites that take the worst form of thermal cycling abuse are the solar panels. Solar panels are made from many layers of materials and are directly exposed to sunlight. This makes the parts especially susceptible to thermal stresses. Solar panels are also highly important parts since they power the satellite, meaning the life of any given satellite is directly dependent on how long solar panels last while in service. The longer a satellite can last, the more cost-effective its operation.
In order to predict the anticipated lifetime of solar cells (also known as coupons), NTS has conducted tests on different solar cells to simulate the kind of temperature cycling that would be experienced while in orbit. In one of our tests, we placed some coupons in a chamber with an atmosphere of nitrogen and used a special lamp to heat them up. Followed by heating, we rapidly chilled the nitrogen atmosphere to cool the coupons.
This process was repeated multiple times in rapid succession to simulate about 1.5 times the number of anticipated thermal cycles during a satellite’s lifetime. Some types of coupons survived the test, and others did not. However, our testing helped us confirm the best candidate materials and exclude those that were most likely to fail too early in the satellite’s lifecycle to be acceptable .
Environmental testing sounds simple enough in theory, but there are some real challenges when trying to design a product for its environment. How are engineers supposed to predict how given product designs will perform before they have been in actual service for a certain time period? Without some type of carefully planned environmental testing strategy, designing for the operating environment is educated guesswork at best.
There is simply too much risk involved with releasing untested or marginally tested products to market. On the other hand, time to market is a real concern to companies that wish to remain competitive. In other words, companies don’t have enough time to build prototypes and test them over their intended lifecycle with normal use before releasing them to market. This is why better strategies are required — preferably environmental testing strategies that can reliably and sufficiently accelerate the aging and wear placed on test items.
Over 50 years of testing gives NTS the experience needed to help predict anticipated product performance with a reasonable degree of confidence. Most of these methods fall under the generic category of simulated environment testing since the simulated test environments attempt to produce the anticipated types of stress on products. Such testing attempts to validate or improve product designs and manufacturing processes.
Certain environmental simulation testing methods can actually go far beyond any environmental conditions that products are expected to experience in order to prove increased degrees of robustness and reliability. Whatever the case, simulated test environments are intended to verify that products are ready for customers by ensuring that they can withstand their intended environments.
The Purpose of Environmental Simulation Testing — Why Do It?
There are several good reasons for your company to perform environmental simulation testing, and it’s especially important to the overall success of your business. These reasons include:
1. Testing is required.
Testing to specific standards and requirements is almost always a requirement of doing business. Customers like Boeing and Airbus require testing to the DO-160 standard. Department of Defense contracts require conformance testing to MIL standards like MIL-STD-810 for any systems or subsystems used in defense of our nation.
2. You want to set yourself apart from the competition.
Even if testing to MIL-spec standards is not a requirement for your specific market, many consumer electronics and devices are being marketed as meeting military standards — providing them with a distinct competitive advantage.
3. You want to avoid litigation.
Many lawsuits are frivolous and outright unjust. Few people are willing to argue this, yet lawsuits are a fact of life. Nevertheless, the best way for a company to avoid litigation is to be above reproach, which includes testing products to ensure they meet their specifications. That way, mishaps due to flawed products are unlikely — and even if something goes wrong, the company can demonstrate in a court of law that it performed its due-diligence and is not to blame for the failure.
4. Standards require environmental testing.
There are cases where environmental testing is not explicitly required to comply with laws or contractual requirements. However, in order to comply with established standards, manufacturers need to perform environmental testing on their products. Voluntarily complying with established standards and certifying them will increase the marketability and credibility of your products, granting a competitive edge over manufacturers that do not bother to test or certify their products.
5. You want to improve reliability or validate a design.
Simulated environment testing can expose many design flaws early in the design process, so your designers can remediate the flaws or make improvements. Likewise, environmental testing can expose flaws in manufacturing so your company can correct its process and avoid excessive warranty claims.
The iPhone 6 and iPhone 6Plus are well-known cases where environmental testing could have caught a design flaw. These phones were known to bend and break as people were accustomed to carrying them in their back pockets. The new designs should have been evaluated in all environments, including the back pocket.
Based on these reasons alone, perhaps the question becomes: why not perform environmental testing?
The Benefits of Environmental Testing
In cases where environmental testing is not required by contract or law, the biggest benefits are gained by increasing product reliability and decreasing risk associated with product development. But what about cost?
When it comes to environmental testing, some costs can be quantified and others cannot. The costs that can be quantified are the estimated cost of environmental testing versus the total cost of recalls, warranty claims, lost productivity, and other losses incurred by defective products. These are values that can be quantified from existing data. The benefits of environmental testing rely on business dynamics that don’t exist before an environmental testing program is implemented, and competitors are unlikely to share any internal data about these matters.
The best way to see if a simulated environment testing program is financially viable is to see if the estimated cost of testing is acceptably less than the total cost of failures. Simulated environmental testing introduces negligible risk into production lifecycles and is also likely to reduce overall risk.
In an ideal case, implementing an environmental testing program would enable a company to reduce product development time, theoretically reducing development costs at the same time. Once a product is developed, the company should understand the product’s life expectancy and be able to reduce the amount of warranty claims due to enhanced quality. This reduces maintenance and customer support costs. Since better products tend to produce more customer satisfaction, sales should also increase. All of these benefits add up to greater profitability for your company.
To reinforce this idea even more, customers tend to fixate on negative characteristics as opposed to positive characteristics. And because bad news travels quickly and efficiently, companies must invest in upholding their name and reputation. One way to invest in upholding your company’s name and reputation is to invest in continuous product improvement. To invest in continuous product improvement, you can consider investing in the types of testing that will enable realistic design validation and facilitate effective quality control.
When you spend your time and money on properly validating products, your bottom line is less likely to be negatively impacted by lawsuits, bad reviews, bad press, and disgruntled customers.
The Methods — How Is Simulated Environment Testing Performed?
Over the decades, environmental testing engineers have contrived many types of tests designed to simulate the types of wear and tear that environments are expected to inflict upon the items of interest. Frequently, environmental simulation testing involves attempts to speed up the wear and tear process to the point where a given test item may experience a full lifetime’s worth of wear and tear within a few days or weeks. This is exactly what we achieved when testing solar cells for satellites.
Sometimes, companies may utilize certain types of testing equipment to demonstrate the durability of their products. In one example, Ford Motor Company worked with NTS to use one of our centrifuges in order to demonstrate the strength of their F150 series pickup truck. Their mantra is “Built Tough,” which is why Ford wanted to highlight the durability of its products. Ford asked us to swing one of its 2008 F150 pickups around on one of our large centrifuges using the truck’s front tow hooks. The goal was to demonstrate that the tow hooks, as well as the rest of the truck, could withstand 6gs of force. This demonstration was used in Ford’s 2008 Superbowl commercial.
Even if you don’t manufacture cars, different applications require different types of testing. This is where NTS comes into the picture. In the world of simulated environmental testing, our engineers can simulate many types of conditions. Here are some examples.
- Dynamics Testing
Dynamic testing is a broad category that involves testing items against conditions such as acceleration, vibration, fatigue, shock, drop, etc. The basic idea is to apply various types of physical stresses to test items to see if they can withstand them. Aside from swinging a pickup truck around on a centrifuge, we can simulate the stresses involved in rocket launches, fast flight maneuvers, impacts, changes in pressure, and more.We can even engineer special tests for special applications. The F150 centrifuge test is not a typical test, but we created the test so Ford could demonstrate the toughness of its truck for advertisement purposes. If you have special needs in mind for a particular test, we can work with you to find the ideal solution.
- EMC/EMI Testing
Over the years, electronic components have become smaller and more sensitive to electrical disturbances. Certain types of electronic components are also sensitive to other types of radiation. At the same time, electronic components have been employed in more safety and mission-critical applications. For this reason, electrical and electronics engineers need to take special care to ensure their designs are resistant and fault-tolerant to electromagnetic disturbances. At NTS, we routinely test electronic equipment to ensure they meet operational standards for their anticipated environments.Likewise, many types of electronics equipment require tests to ensure they don’t emit unwarranted amounts of electromagnetic radiation. In this case, the goal is to prevent electronic equipment from interfering with the operation of other nearby electronic equipment. The FCC, the DoD, and other agencies all have relevant standards for this type of testing.
- Materials and Chemical Testing
The best way to see if a material is suitable for its environment is to exaggerate the environmental conditions that it will experience in its given application — and see how the material changes its properties. In the case of testing satellite solar panels, the goal was to see how the solar panel materials withstood repeated thermal cycling. Other environmental tests may measure corrosion or chemical resistance as well as reactions to UV exposure.Another category of materials and chemical testing involves testing the properties of hazardous materials. If a material is suspected to be hazardous, its properties need to be quantified and qualified in order to implement proper handling measures.Some known hazardous materials also need to be packaged in a way that is safe for shipment. The only way to determine whether or not they are safe for shipment is to perform environmental testing. This means packages should be exposed to temperature changes, drops, shocks, vibrations, and simulated altitude changes to ensure nothing bad can happen during transportation. NTS routinely performs this type of testing on lithium batteries so they are deemed safe for shipping.
- Other Types of Environmental Testing
Nearly every type of testing involves manipulating environmental factors to determine whether or not the product will perform satisfactorily. Environmental testing is a broad category. Environmental simulation testing may involve changes in heat, pressure, humidity, moisture, UV exposure, weathering, etc., and these environmental simulations may be performed in conjunction with any combination of dynamics and materials testing.
NTS engineers are experts at contriving simulated test environments to include any combination of testing methods. We can customize them according to your needs.
If you have any questions about how an environmental testing program can help your business, contact our team today.