-
September 7, 2024
Mechanical testing is a core quality control process in manufacturing that guarantees that a product performs as originally intended. It requires engineering knowledge and expertise, as well as a deep understanding of quality standards, procedures, and documentation.
This article will discuss the mechanical test process and various types of mechanical testing methods.
Contents
hide
I
What is Mechanical Testing?
II
Why is Mechanical Testing Important in Manufacturing?
III
General Types of Mechanical Testing
IV
Special Types of Mechanical Tests
V
Is it Necessary for Manufacturers to Invest in Mechanical Testing?
VI
WayKen Ensures Your Maching Projects with High Specification
VII
Conclusion
VIII
FAQs
What is Mechanical Testing?
Mechanical testing is a part of manufacturing quality control where a mechanical test engineer performs various systematic, standardized tests on a part to check its performance in real-life working environments.
The mechanical test process is a necessary part of product development and manufacturing. It acts as a final stamp for the entire product development process, verifying that each step from beginning to end is a viable one. Successful mechanical testing gives investors and engineers the confidence to go ahead with full-scale production.
What’s more, these mechanical test procedures are very well-regulated. There are dedicated mechanical testing standards by international organizations like ASME, ISO, and SAE for a variety of mechanical tests, conditions, and industries.
Why is Mechanical Testing Important in Manufacturing?
There are several reasons for manufacturers to develop their expertise in mechanical testing and invest in establishing quality procedures as per guidelines set by well-recognized standards.
Quality
Ensuring high product quality is inarguably the top priority of manufacturers. Consequently, the number one reason for having a proper mechanical testing setup in place is to meet quality standards.
Providing a documented guarantee for critical quality issues like material testing, load-bearing capacity, and dimensional accuracy can elevate the chances of a product being preferred by consumers.
For instance, performing a mechanical test to check the chemical composition of raw materials is an important quality procedure. Using a low-quality raw material can cause product failures, equipment damage, and time wastage. As a result, manufacturers employ mechanical testing to avoid such quality issues.
Safety
Another major reason for implementing the mechanical test process is to enhance product safety. By conducting adequate quality tests, a manufacturer can assure its customers that their product is safe to use.
This is a big concern when launching new products or starting a large-scale production. There must be a solid guarantee of user safety. For example, consider a critical component like a car axle. Having a weak design or bad production process is unaffordable as it jeopardizes user safety.
For these reasons, safety testing is a big part of quality procedures like first article inspection, where manufacturers rigorously check for faults with safety concerns in order to eliminate them before they appear on a bigger scale.
Research & Development
Conducting research and development activities is an important aspect of product development in manufacturing. Most companies spend a lot of effort developing new products or introducing better variants of existing products into their product lines.
Apart from design innovation and advanced production techniques, mechanical testing is one of the fundamentals of this process. After developing a new product, a mechanical test engineer puts the prototype through rigorous testing routines for different performance and failure criteria.
General Types of Mechanical Testing
The mechanical test process is very wide-ranging. There are several types of mechanical testing options available to a mechanical test engineer. In this section, we will discuss the most common tests that engineers use.
Stress Testing
Stress testing is the most common mechanical test in manufacturing. It checks the stress response of the product under the various kinds of mechanical loads the product is designed for. For example, steel cables for bridges need to be capable of withstanding high tensile forces, so they must pass a mechanical test for tensile stress.
In other cases, stress testing can reveal problems like stress concentrations that are easily avoided. For example, a stress test may reveal that a product experiences failure-level stresses at sharp corners. Mostly, such corners are replaceable with better-suited fillets. All it takes is an additional round of design for manufacturing analysis to fix such issues and prevent loss of time and money on the production line.
Similarly, other stress tests include compression, shear, and torsional stress tests, which are performed based on products’ specific applications. Typically, engineers use equipment like stress testing jigs and strain gauges for stress tests.
Hardness Testing
Hardness, strength, and stiffness are important mechanical properties for manufacturers. It is a measure of how durable the surface of a product is against damage like scratching, denting, or craters. It is relevant for products like bearing balls, which even minute surface damage can cause catastrophic failures.
Typical hardness tests like the Rockwell test, Vickers test, and Brinell test are quite common for characterizing the hardness of a surface. They use specially designed indenters made of a hard material like diamond to create an indentation on the surface using a mechanical tester.
Then, based on how deep the indentation is and how much force it takes; a hardness score is assigned to the surface. This score then determines if the part passes the mechanical test or not.
Fatigue Testing
Fatigue testing is useful for products that go through cyclic loading. This means that the mechanical loads on them are dynamic, and they change in both magnitude and direction with time.
An automotive power transmission shaft is a good example of this. They undergo cycles of both tensile and compressive loading as they rotate at high speeds. Due to this cyclical loading, performing static stress tests on the shaft is not enough. Therefore, it must also pass a fatigue test which puts it through a similar dynamic load as in a car.
Generally, in a fatigue test, parameters like the cycle frequency, number of cycles, and loading types are used to create the setup and verify part performance.
Impact Testing
Impact testing is another common kind of mechanical testing. This is for parts that take high-impact loads. For example, car bumpers. If a bumper breaks upon impact, it is a bad design that is unsuitable for cars.
Therefore, in an impact test, engineers apply impact loads with a known force, time period, and number of cycles to determine impact strength.
Creep Testing
Creep stress is a special kind of stress that develops in a part due to exposure to loads over a long period of time. It causes it to weaken over the course of its service life. For example, a new turbine jet blade is not the same as an old one due to the constant cyclic loading and temperature changes in a jet engine.
In a creep test, engineers simulate these conditions in a laboratory environment and measure how much creep develops in the part over time. To pass the quality criteria, the part should retain a minimum strength level after a certain period.
Special Types of Mechanical Tests
The mechanical test processes in the previous section were a small portion of the entire range of tests. There are many other types of mechanical testing that engineers use for special-purpose applications.
Generally, these tests come in handy for custom manufacturing projects with unique attributes, or for products in special machinery. In this section, we will introduce some of these special types of mechanical engineering test procedures to show the depth of this field.
Tribological Testing
Tribological testing is the evaluation of materials and surfaces for their performance under conditions involving friction, wear, and lubrication. It is very useful for products with interacting surfaces or surfaces with relative motion between them.
For example, two of the common tribological properties to test are friction and wear. For products like automotive brake pads, it is very important to pass quality tests for both these characteristics.
Dynamic Mechanical Analysis
Dynamic mechanical analysis refers to a series of mechanical testing methodologies that evaluate the performance of products under dynamic loads. The common tests in this category test products for strength, vibration, and acoustic response at different kinds of dynamic loads.
For instance, a CNC machine spindle is subject to dynamic cutting loads across a wide frequency spectrum. Therefore, the vibration profile of a CNC spindle should be such that it does not vibrate excessively at any of its operating frequencies.
For such tests, engineers use equipment like vibration shakers, oscillation/drive units, and data acquisition systems.
Leak Testing
Leakage is a big problem in products that carry or transport fluids. Leak testing is a must for such products.
Generally, there are several methods a mechanical tester may adopt for leak testing. A common method is the pressure decay test, where the fluid pressure is checked at regular intervals to check for leakage. A drop in pressure is a sign that there is leakage.
Other popular methods include ultrasonic testing and dye penetrant tests, which are useful in catching leaky pipes, tankers, or weld joints.
Cryogenic Testing
Cryogenic testing is a special-purpose technique suitable for products that work in very low temperatures, typically below -150°C. The mechanical test engineer monitors characteristics like material properties, dimensions, conductivity, and leaks at these temperatures to determine the compatibility of the product with its thermal environment.
An example of this is rocket fuel tanks, which store liquid oxygen and liquid hydrogen at cryogenic temperatures.
Burst Testing
Products like high-pressure vessels, tankers, and tires are susceptible to bursting. Understandably, manufacturers practice extra caution in this case due to safety concerns.
Burst testing is a catastrophic mechanical testing routing, where the test engineer keeps increasing the pressure until the product bursts or exhibits other signs of mechanical failure. The failure pressure and type of failure provide useful information on the manufacturing quality of the product.
Is it Necessary for Manufacturers to Invest in Mechanical Testing?
One of the key factors in setting up a manufacturing business is the decision to choose areas to invest in. While investors rightfully weigh the pros and cons of investing in things like equipment and labor, having the same approach toward mechanical testing is pretty much out of the question.
The mechanical test process is inseparable from the manufacturing industry. It helps manufacturers meet requirements set by international quality standards, improve the quality of production, and achieve customer satisfaction. These factors are important for running a successful business. Most importantly, all these directly contribute to profitability, and therefore justify the decision to invest in mechanical testing.
In this regard, manufacturers should at the very least look to procure appropriate quality testing equipment based on the types of mechanical testing they expect to conduct, hire a qualified mechanical test engineer, and a dedicated software to manage the mechanical test process.
WayKen Ensures Your Maching Projects with High Specification
WayKen, as a professional rapid prototyping company, ensures your machining projects meet high specifications by using advanced technologies and mechanical inspection during the production process. With engineering expertise and strict management processes to quality standards, such as ISO 9001, WayKen guarantees that your CNC machined parts are of high quality, reducing failure risks and improving overall performance for demanding applications.
Conclusion
Mechanical testing is one of the foundations of the manufacturing industry that covers various types of mechanical testing procedures, international quality standards, and engineering expertise. It is a great way of enhancing your business’s profit margins by showing customers that you are serious about producing high-quality products and value customer satisfaction.
FAQs
How to define mechanical testing requirements and guidelines?
Mechanical testing requirements and guidelines are defined during the product design stage. Testing requirements are decided based on the product application. For example, a high-temperature endurance test is necessary for a product that is supposed to work in elevated temperatures. For guidelines, there are several defined standards like the ASTM A370 with detailed frameworks for executing mechanical testing procedures.
When is mechanical testing performed during a manufacturing cycle?
Generally, mechanical testing is performed during the quality control phase of the manufacturing cycle, after the production has finished. However, certain tests may also be conducted during production to catch faults early on.
Who is involved in mechanical testing in a manufacturing environment?
Quality control professionals like QA/QC engineers, testing technicians, materials engineers, production managers, and calibration experts.
Keyword: Vacuum casting
Recent Comments