As Vibration Consultants and Acoustic Consultants, Response Dynamics works within the United States and worldwide to provide unmatched services in advanced vibration analysis, acoustic analysis, vibration testing, acoustic testing, vibration monitoring and noise monitoring services, as well as engineering design. For 35+ years we have combined our engineering test and analysis expertise in areas relating to vibration, acoustic noise, strain, thermal heat flow, airflow, and magnetic field, with our system and facility troubleshooting and design consulting expertise. We take pleasure in sharing our specialized knowledge and skills as a part of our clients' teams. Please feel free to call us to discuss your team's product, system or facility issues.
We have worked on a myriad of systems and facilities, with responses ranging from subnanometer amplitude disturbances of electron microscopes, interferometers, and atomic force microscopes, to micron amplitude motions of giant telescopes in Hawaii and in the Chilean Andes, to meter amplitude storm response of offshore oil rigs, to name just a few. (See our Client list by industry).
Industries and Projects Spanning 9 Orders of Magnitude
Working in the roles of vibration consultant, acoustic consultant, and EMF consultant, we partner with R&D teams, on the design and development of hundreds of critical systems, products and facilities.
We have worked on hundreds of systems and facilities for high-Tech and Heavy-Industry.
High Tech Industries include:
Aerospace and Defense
Electric & Hybrid Vehicles
Power Generation & Alternative Energy Systems
We characterize complex (often multi variable) problems, design tests to diagnose the root cause of the issue, and to provide engineered solutions (See Industries).
Often times vibration problems and acoustic noise problems can be very complex and subtle. As a result, it is often our role as the Vibration Consultant, or Acoustic Noise Consultant, to perform vibration analysis, vibration testing, acoustic analysis and acoustic testing to develop an understanding of the problem and to provide a means for the rest of the design team to directly visualize the problem, whether it is the vibration deformation mode shapes associated with problem resonances, or with the distribution of the acoustic noise power radiating from a complex product.
Once the design team can visualize the problem, developing the solution becomes much more straightforward. It is a little like the children's party game of pin-the-tail-on-the-donkey; Our job, as the Vibration Consultant or Acoustic Noise Consultant, is to take the blindfold off of the design team so that they can easily hit the target, instead of the frustrating, time-consuming and expensive, trial-and-error process that the team had been struggling at when blindfolded.
Response Dynamics has made Diagnostic Vibration Testing and Diagnostic Acoustic Testing our bread and butter work for more than 30 years. We enjoy this work, and we do it well because we are well grounded in basic applied physics, digital signal processing, structural dynamics and vibro-acoustics, and how they relate to system and facility vibration and acoustic noise issues on a myriad of levels.
We are expert vibration consultants in resonance testing, Modal Analysis, Operating Defection Shape Testing (ODS), as well as both Steady State and Transient Analysis, with literally decades of experience developing our detailed methodologies that produce meaningful results.
Fundamental to Dynamic Testing are Frequency Response Functions (FRFs). As Vibration Consultants and as Acoustic Consultants, we design tests and/or analyze frequency response functions (FRFs) almost on a daily basis. These FRF measurements form the basis of modal analysis and the theory of linear system structural dynamics. We are fluent in spectral analysis and the digital signal processing inherent in the vibration analysis measurement process, and thus we can spot problems before they corrupt a whole data set, or an entire project.
Tools of the Trade for Structural Dynamics Testing
Non-linearities exist in all physical structures and are often not a problem. However, when they are involved, we know how to spot them and deal with these unique dynamics. While performing vibration testing, the choice to use electro-magnetic shakers, force hammers, or known inertial loads as force inputs depends on the nature of the system dynamics, the response amplitudes, and the transient/steady state characteristics of the vibration issue. We have refined these vibration consulting skills for more than 30 years.
The physical principles of structural dynamics, acoustics, optics, and thermodynamics apply to structures and systems large and small. The wide variety of our projects keeps our work interesting, after all these years, even as we apply the same fundamentals again and again.
Meaningful Test Data, Knowing Good Data From Bad
We use our vibration testing and noise testing expertise, as well as various methods of analytic, computer modeling and Finite Element Analysis (FEA) to make sense of the complex vibration problems and noise problems, thereby enabling efficient solutions.
Strain Gage Testing and Stress Analysis of Fan Blade for FEA Validation
The nuts and bolts of knowing good data from bad brings indispensable value to our analyses.
We also make an effort to know what we don't know by considering measurement error, instrumentation noise, resolution limitations, and non-linear behaviors. See our discussion on Product R&D
Experimental Design: The Most Important Step
We focus on the important dynamic parameters of the system and its boundary conditions, and design tests to prove or disprove hypotheses. When performing vibration analysis and vibration testing, there are countless ways to create erroneous results. It takes effort and experience to extract meaningful results, interpret them, and then engineer creative and sound solutions. Whether it involves testing in the cleanroom instrumenting a delicate optical interferometer using a tiny non-contact capacitive sensor, or climbing through a power plant structure running hundreds of feet of cable to an accelerometer array to troubleshoot a Turbine Isolation Issue, we often employ many of the same principles, concepts, and methodologies of vibration analysis and acoustic analysis.
We know from our extensive experience as Vibration Consultants and as Acoustic Consultants that the initial assessment is critical to asking the right questions at the start of investigation. These questions will lead to a set of initial hypotheses about the issues at hand. A sound foundation of vibration and acoustci noise theory, basic physics, strong mechanical intuition, and years of structural dynamics experience are necessary to design an effective set of tests.
120 Megawatt Steam Turbine, Concrete Turbine Pedestal, and Steel Building Structure, Using Thermal Analysis and Operating Deflection Shape Testing (ODS)
Semiconductor Inspection Tool Testing Using Sub-Nanometer Capacitive Sensor Between Wafer and Optics Plate
The limitations of where instrumentation can be placed, the inherent sensor limitations, and the impact on the system dynamics need to be considered. Thus, designing the experimental setup to extract meaningful vibration analysis and acoustic analysis results is perhaps the most important step in solving a pressing issue where time, patience, and resources are in short supply.
We most often characterize a problem first and work from known conditions, and stay in “the known” as we proceed by making sense of what we observe as we move forward. This is very important. We test and analyze the change in dynamics we are trying to create in real-time, on site, and often make changes to our experimental test plan on the fly as we discover how a system is actually behaving. In doing so we often get meaningful results from which we can make sound engineering decisions in a short time frame. We do NOT make measurements and spit out data.
We are well versed in vibration testing and acoustic noise testing instrumentation, digital signal processing, and spectral analysis. As Vibration Consultants and as Acoustic Consultants we use our specialized skill set, and a vast selection of instrumentation that we have collected for over 3 decades, to design tests and solve complex problems.
Multivariable testing is usually necessary to really get a handle on an issue involving multiple disciplines of physics. We design tests to measure static and dynamic strain, acoustic noise static and dynamic pressure, vibration acceleration, velocity and displacement, magnetic field, temperature, fluid flow, and light intensity, to name a few.
Real world problems involving the measurement of multiple variables require an understanding of the physics of the coupling between them, as well as the physics and limitations of the measurement instrumentation. Problems in different frequency ranges necessitate unique approaches involving instrument selection, mounting dynamics, cabling, and coupling with other structures and media.
Measurements of Ambient Acoustic Noise, Floor Vibration, and the Frequency Response of the Semiconductor Tool Response Showing Resonances that Dictate the Disturbance Response of the Tool to the Environment
For instance, when a consumer product is too noisy, a bedside medical device for example, in addition to the acoustic analysis and testing, thermal analysis and heat flow optimization of the cooling system will often be part of the acoustic solution, in addition to Damping Treatments, motor vibration isolation, etc., based on vibration analysis and testing results. In debugging scanning electron microscopes (SEMs) issues, disturbances due to acoustic excitation, floor vibration, control instability, frame resonances, thermal drift, and magnetic field all superimpose to create a confounding image disturbance. Additionally, each of these disturbances can be aliased. We have years of experience untangling overlapping disturbances involving multiple sources to make the issue understandable, and allow for educated decisions when weighing different solution strategies.
We very often get our hands dirty and build proof-of-concept “fixes” on site, or back in our shop, to quickly perform a vibration test or an acoustic test a “design-fix” concept, based on our vibration analysis or acoustic noise analysis. We do this prototype testing carefully, with more than 30 years of structural dynamics and acoustics experience as vibration consultants, always working hard to test and keep an accurate understanding of the current system dynamics and the boundary conditions associated with our vibration testing and vibration analysis as we make changes.
Tuned Mass Damper Design for Biotech Optical Tool
However, as so often happens to our clients, when quick and dirty fixes are attempted by other engineers with little structural dynamics experience, confusion, delay, and uncertainty regarding the design of the experiment often result. A faulty vibration test often leads to the wrong conclusion and drives the wrong action path away from a good solution. Valuable development time is often wasted, and the issue soon becomes an emergency. For more detailed breakdown of this See our discussion on Product and Facility Emergencies.
We have the experience as vibration consultants and as acoustic consultants, to quickly analyze past test methodologies and explain for the team what has been done well, and what needs improving, tweaking, or additional attention to a particular dynamic parameter. This is important for getting an engineering team all on the same page by making sure everyone understands the problem, what has been done, and how to move forward. These unique abilities have brought us long lasting working relationships with our clients.
Starting From Scratch, The Design Phase, Facility and Product Development
We enjoy being part of the team in the design phase. We help get the design right from the 1st alpha system to avoid last minute emergencies. We have recently worked in the design phase performing analytical and experimental vibration analyses on a table top scanning electron microscope, a table top genomics ID system, and worked though the design and test of a cutting edge bio-tech imaging system with 25 nm resolution that will perform on upper floors of light construction. As vibration consultants and as acoustic noise consultants, we have quieted noisy dialysis machines, eye surgery equipment, surgical robots, semiconductor imaging tools, and multi-ton solar tracking arrays.
On new Facility Design projects, with unique acoustics and vibration needs, we perform the roles of Vibration Consultant, Acoustic Consultant and EMF Consultant, as a part of the Architect's Team. These facilities include state of the art semiconductor research facilities, university research buildings, tech-group collaborative office spaces, and others.
Tuned Mass Damper Design for Biotech Optical Tool
Visualization of a Floor Resonance Measured at a Surgical Facility Using Modal Analysis Field Testing
New facility design considerations that require our expertise include HVAC acoustic design, mechanical room design, equipment vibration isolation mounting, sensitive tool placement, floor system design, wall and partition design, sound masking, active cancellation of vibration and acoustic noise, passive acoustics (added reverberation, or added sound absorption in particular frequency bands).
Acoustic Analysis Results Comparing Sound Levels with NC Noise Criteria
As Vibration Consultants and Acoustic Noise Consultants for design of new High Tech Facilities (such as: Semiconductor, Biotechnology, Pharmaceutical and Nanotechnology facilities), we not only have the expertise in the testing the building floor dynamics, vibration, and acoustics, but we understand the needs of the high resolution sensitive equipment used in these facilities because` we design, fix, and test this equipment. We perform the Sensitivity Testing and write the specifications for some of the high resolution imaging and testing systems used in these industries. Additionally, we have spent decades working with facilities teams to troubleshoot their facility issues and thus we have intimate knowledge of what issues to expect and how to prevent them. We translate that knowledge into design specifications and work with the design team on these critical design details.
Comparison of Vibration Sensitivity Modeling with Experimental Test Data Used to Evaluate Structural Modifications for Performance Improvements
Some of the clients we have worked with over the years, as Vibration Consultants, now manage engineering groups. It is these past clients that most often call us in the design phase of the product where we provide very valuable input in design reviews helping to show where potential pitfalls may found, and where great improvement may be had by the adjustment of a few engineering details. Our input in the design phase will save valuable development time and resources, and has proven to be a key to the success of many product R&D efforts.
In product development we provide assistance at several points along the product development cycle. Firstly, we provide assistance and guidance in the development of conceptual and detailed design (often using a combination of analytic, numerical, and Finite Element Modeling. Our extensive experience as Vibration Consultants allows us to see potential pitfalls and find winning solutions, as part of your team, in the start of the design process. This is critical to staying on budget, on schedule, and meeting performance goals.
Once the prototype has been built, we perform vibration measurements and vibration analysis of the dynamic response of these systems to expected disturbances, including both internal vibration and acoustic noise sources (such as X-Y stage stopping transients) and external sources (such as floor vibration and HVAC acoustic noise). In addition, determination of system resonances by Modal Testing and analysis often provides critical design information. If necessary, the design is then improved by making appropriate changes in structural design, Stage Control, Vibration Isolation, and Damping Treatment.
Effective Damping Treatment Design Is Possible With a Thorough Understanding of the Structural Dynamics of the System
We may also suggest modifications to control system parameters or other system changes. We use our testing and analysis to explain why a system performs as it does, and why the modification will improve performance. Our experience as vibration consultants allows us to be both efficient and thorough, minimizing troubleshooting, tool time, and prototype iterations.
For tool vendors, we perform vibration Sensitivity Testing to determine the specification for allowable levels of Facility Vibration and facility acoustic noise for the system's installation. We also perform Site Evaluation measurements to verify that the proposed installation site (in the end-user's facility) provides an acceptable vibration and acoustic noise environment for the successful operation of the sensitive system. If facility problems are identified at an installation site we often work with the owner's facilities team to identify and solve the problem or to find a suitable alternative site for the system. The solution may involve reduction/isolation of the disturbance source, active cancellation of the disturbance at the sensitive tool, modification of the floor system, or tool improvement (such as with tuned mass dampers).
Some of the metrology tools that we have worked on as vibration consultants are SEM tools, FIB tools, TEM tools, AFMs (atomic force microscopes), stylus profilometers, wafer steppers, interferometers, electron microscopes, CD SEM tools, elipsometers, and SPM tools which are manufactured by the companies such as KLA-Tencor, Veeco, Applied Materials, Rudolf Technologies, Nikon, Wyko, Zygo, Sensys, JEOL, Amray, Schlumberger, Thermawave, FEI, and Nanometrics.
This video was produced with material gathered during our many years as vibration consultants, of field vibration testing and highlights some of our projects involving modal analysis testing
Whether making a few dynamic measurements, or performing a full modal analysis test, or working on the R&D of a new sensitive tool or critical facility we use our extensive experience to efficiently achieve the project goals. Our founder, Reuben Hale, P.E. started the company over 30 years ago in 1984, and our VP of Engineering, Henry Bittner, MSME, has been with our company for more than 24 of these years (since '93). Similarly, our other senior staff member, Susan Reno MSE is also extremely skilled and an experienced vibration engineer, having more than 10 years experience working with Response Dynamics. We love what we do and are at the very top of our unique field.
Our extensive Client List represents hundreds of projects, some involving days of work, others lasting several months, over the last 30+ years. Descriptions of many of our projects can be found in this website's left hand links, under the various topics that describe our test, analysis, and design work.