X-High is company for performing modal testing and surveys to characterize structural dynamics.

We have been providing this service, having pioneered numerous technical capabilities including random excitation, multishaker testing, polyreference data processing, and automated test setup processes. Our ability to deploy well over 1000 channels of instrumentation and data acquisition equipment allows us to complete modal surveys of almost any size structure. We specialize in aerospace structures (aircraft, space launch vehicles, rocket motors, and satellites) but can test virtually any dynamic system.


Testing of structures and systems in normal operation can be fundamental to verifying that everything is operating properly. High vibration levels are often indicative of out-of-tolerance conditions such as imbalance, bearing failure, and poor lubrication, and they may also indicate a resonant condition that was not anticipated during design and installation.

Operational testing is critical to verifying system performance and can lead to a better understanding of overall system health. This type of testing can also help identify and understand the loading conditions that are present during operation. Troubleshooting and operating evaluation can prevent future failures and improve system performance. This type of testing spans all industries—aerospace, automotive, industrial, manufacturing, etc.—and the structures and components present in them.

Drop & Shock

Shock conditions cover a variety of conditions which can include dropping onto a hard surface for many commercial products or pyroshock conditions that take place in many aerospace components. These transient, high amplitude events can be extremely damaging to structures and subcomponents, with overall catastrophic results.

Shock testing is often performed as part of a hardware qualification or design process. Information obtained during shock testing can improve the survivability of products and verify that they will perform properly in service. Special consideration is usually required for this type of testing because it often consists of a one-time event or is too expensive to repeat. While backup data acquisition systems are sometimes needed to minimize risk, these types of tests invariably require special transducers and measurement systems to record and process high-level, high-frequency response.

X-High has these specialized transducers and measurement systems along with the personnel to assist in their installation and use. Further, X-High has expertise in analyzing and testing for shock environments of all types. Our instrumentation enables the high-level and high-speed acquisition of shock behavior to verify the structural shock environment exposure.

Test Analysis correlation

Analysis models can be effective predictive tools for confirming that a structure has met its design goals—but only when the model matches the physical hardware. Using testing to correlate the finite element model (FEM) to the physical hardware is an important step in building confidence in the model’s predictive capabilities.

Test–analysis correlation is the critical step in adjusting the FEM to minimize the differences between the test results and the FEM predictions. In the case of modal testing, this involves adjusting the FEM mass and stiffness properties so that they are consistent with the test configuration. For static and dynamic loads analysis, correlation of testing results for specific load cases can be done to validate model predictions.

X-High’s expertise in performing analysis, often in preparation for a testing program, means that we are perfectly suited to the test–analysis correlation process as well. Our analysis and test engineers work closely together and often participate in all phases of modeling and testing activities.


Validation of how structures carry load and what kind of stress distribution exists is important for confirming structural design and integrity. Analysis predictions provide critical guidance in the design process, while testing provides confirmation of the analysis model’s predictive capabilities and the physical hardware’s performance. Strain testing is a direct approach for obtaining the information necessary to build confidence in a structure’s ability to perform as designed.

Strain testing allows both static and dynamic loads to be evaluated and can be used to troubleshoot existing systems to identify when there may be problems. When a structure has failed, strain testing can guide the detailed evaluation to determine the loading conditions that led to the failure. Strain testing allows the true environment to be identified to assess whether fatigue or overload conditions exist. Coupled with finite element analysis, strain testing allows thorough structural assessment for design validation. X-High is expert at conducting strain testing on existing structures at remote locations in the field.