Vibroacoustic testing is an easily integrated inspection method into automation environments, offering numerous technical advantages that help increase productivity while decreasing pseudo rejects and maintenance costs.
Fetal vibroacoustic stimulation was found to induce vigorous fetal movements in 12 randomised controlled trials (6822 women). It’s simple and cost-effective; thus enabling clinicians to reserve more serious interventions like cesarean birth for those fetuses that truly need it.
Non-destructive testing
Noise and vibration testing is an effective method for uncovering hidden product defects that haven’t been noticed by inspection so far, from slight imbalances of bearing parts to production errors in an automobile engine’s cam or pinion system.
Quality production plays a key role in any company’s commercial success on the market, which is why 100 % inspections and zero-error tolerance are now standard in most manufacturing processes. Objective quality controls in production lines are required to avoid customer complaints or false rejects and optimize production process performance.
Vibroacoustic testing is an efficient, quick and non-destructive testing technique used to detect cracks and determine mechanical properties in material samples. Furthermore, this test method helps assess performance by exciting structures with dual frequency sinusoidal signals and measuring response for changes in vibration characteristics.
Researchers are exploring methods to enhance the damage detection capability of vibroacoustic monitoring in concrete structures affected by alkali-silica reaction (ASR). Their aim is to develop an advanced, high-fidelity machine learning approach for localizing damage in plain and reinforced concrete specimens with unknown locations of damage induction, using dual frequency vibration analysis for measuring structural dynamics as well as mechanical properties like Young’s modulus.
End-of-line testing
End-of-line testing is an integral step in manufacturing, helping ensure products meet all specifications and requirements before leaving the production line. This helps decrease product defects, returns, warranty claims and the associated warranty claims while tracking trends and pinpointing issues; ultimately leading to higher productivity and customer satisfaction.
End-of-line testing entails a series of evaluations designed to verify a product’s performance and functionality, and may include mechanical and software evaluations. Sometimes this testing can even be automated to reduce human error risk – which can be particularly important for highly complex items like electric vehicles and their powering components.
One type of end-of-line test is a vibration test, which checks that a product meets all required standards for function and performance. Acoustic chamber testing or performing the vibration test directly on the product itself may be conducted to detect structural and surface-related problems; noise or buzzing sounds could indicate damage or missing components in its development process.
Functional test stations go beyond vibration and acoustic tests by providing electrical or mechanical functionality analysis for finished products. Testing can either be automated or done manually and can help ensure consistent test procedures across production sites as well as improving manufacturing process efficiency by decreasing human error and cycle times.
Acoustic testing is an integral component of aerospace product design and qualification processes, often conducted in a reverberant chamber to simulate environmental stresses like vibration, temperature fluctuations and acoustic load. Acoustic tests may also be utilized as part of dimensioning or qualifying equipment mounted to aircraft wings or fuselages such as solar panels and antenna reflectors.
ATA utilizes top-of-the-line modeling techniques, such as statistical energy analysis (SEA), boundary element method (BEM), and finite element analysis (FEA). Our engineers use these models to predict vibroacoustic vibration response and correlate results from tests for various structures, as well as perform acoustic evaluations on rocket fairings, satellites, and other structures using these models.
Automated testing
Manufacturers have relied on sound and vibration measurements since ancient times to detect defects in their products. From ceramists tapping freshly finished pottery vases to assess their quality to noise, vibration and structural stability tests conducted during aircraft engine production, sound and noise measurements have long been used as end-of-line test methods to uncover hidden faults; today this tool remains essential in guaranteeing both the quality and durability of technical products.
Objective quality control throughout the production process is indispensable for identifying errors early on and mitigating them, thus improving product reliability and customer satisfaction. Productivity increases thanks to reduced false rejects on the production line. End-of-line testing is an integral component of quality assurance and should be performed regularly when developing or optimizing existing products. As such, accurate measuring technology must provide reliable detection of errors and anomalies while simultaneously offering high test throughput even during complex testing cycles. Furthermore, integration must be easy for various test stand and automated processes. Industrial laser vibrometers from Polytec meet all these criteria and more, offering numerous advantages: maintenance-free operation with adjustable measurement distance and open interfaces allow them to easily integrate into test systems; additionally they feature smart signal analysis in frequency, order, angle, time domains enabling users to identify relevant fault patterns more quickly and efficiently.
Polytec’s maintenance-free IVS-500 laser vibrometer perfectly combines these advantages, providing reliable, flexible and fast good/bad analysis as well as structure-borne sound analysis. Testing may take place both near and far from the object being tested; in confined spaces where tactile sensors and sound insulation chambers would typically need to be installed for testing purposes. So as not to subject the test object to undue stress during measurement and to protect any sensitive components from potential damages or environmental influences. Laser vibrometers also automatically focus on components with variable distance from their base, always measuring with optimal signal quality despite tight spaces, so no preparation of test object or closing sound insulation chambers are necessary to complete measurement/test time effectively. This greatly decreases test and measurement times!
Laser vibrometry
Laser vibrometry is an optical measurement method that quantifies mechanical oscillations. A laser beam is separated into test and reference beams via a beamsplitter; then guided toward an oscillating target surface via the test beam, creating a doppler shift proportional to velocity that is detected by the reference beam which directs itself toward a photodetector that emits frequency modulated signals proportional to displacements (see figure below).
Laser interferometers create a spectrum of light from any measured object by interfering between laser beams. This spectrum can then be analyzed to identify vibration characteristics for analysis; its results can then be used to detect defects and their cause – for instance damage on an engine that leads to noise and vibration issues in vehicles can be easily identified using this test, along with manufacturing quality monitoring processes; they’re even useful for NVH testing which helps determine why excessive noise exists, like engine or transmission noises.
Vibroacoustic testing is an efficient end-of-line process that enables companies to detect errors in their products or production processes before reaching customers, eliminating costly complaints and losing confidence with them. Vibroacoustic testing also reduces repairs/recalls/improves product performance overall.
Laser Doppler vibrometers are highly accurate tools capable of measuring both vibration frequency and displacement, making them useful tools for detecting cracks or flaws in metals and composite materials as well as human tissues such as eardrums. Test results can then be compared with specifications or tolerances to identify deviations from desired states; using such technology can significantly cut repair times as well as loss in revenue.
