Moog CSA provides test services to diagnose the cause of high vibration levels in machinery and precision devices. Vibration can downgrade system performance or cause catastrophic failure. A well-designed test program in conjunction with our design and analysis engineering expertise provides high performance solutions to even the most challenging vibration problems.

We offer a complete package in our vibration test services: test fixture design, test planning development, highly trained test engineers and test equipment. Moog CSA can perform tests in the field or in our laboratories to characterize component performance or diagnostic experiments. Our engineering staff has years of experience in signal processing and will properly interpret measurements that feed into structural modification designs to solve your vibration problem.

Often measurements must be made at our customer’s facility to characterize the vibration environment and identify noise sources or troublesome structural dynamics. We use established test techniques for rotating equipment to identify the cause of the vibration, which is an important step toward implementing an effective structural modification.

Moog CSA has extensive capabilities to characterize components and full systems in our laboratories. Our wide range of instrumentation and actuators can be leveraged to solve your vibration problem with force capacities spanning from ounces to tons.

Specialized test methods we use in the field and laboratory include the following:

• Direct complex stiffness tests to characterize stiffness and loss of materials or structures at controlled temperatures
• Run-up/spin-down with Campbell diagram and spectral waterfall map analyses
• Force state mapping for nonlinear test articles
• Time history-based tests for nonlinear structures

Our years of experience in the modal testing field complement operating measurement techniques. An experimental modal analysis provides estimates of natural frequencies, damping ratios and mode shapes. We use shakers, impact hammers or step relaxation excitation methods based on the test article communicated from a computer hard disk flexure to an aircraft.

Our highly trained testing engineering staff can use portable data acquisition systems for small tests in your facility or our large channel count modal systems for tests that require hundreds of response measurements. Test and analysis techniques can utilize multiple shakers to reduce test time and excite all of the test article resonances simultaneously.

We employ the following approaches when planning for and executing modal tests:

• Pseudo mass cross orthogonality checks for exciter and response sensor location and direction selection as a pre-test analysis
• Model-to-test orthogonality checks for test/model correlation
• Modal assurance criteria checks between model and test mode shapes and test-to-test mode shape checks
• Polar plot analyses of estimated mode shapes

Experimental modal analysis results are instrumental in tuning models. Finite element model development and tuning is one of our core capabilities- it is the foundation for designing and implementing an effective vibration mitigation approach.