ATA are renowned experts in the field of structural dynamics. Backed by more than thirty years of experience, ATA engineers have developed the skills and tools necessary to solve intricate and complex loads and dynamics problems, typically using advanced computational methods including finite and boundary element analysis, statistical energy analysis, computational fluid dynamics and mechanisms. We have worked with many commercial and government customers in diverse fields including the aerospace, defense, entertainment and consumer-product industries. From defining the loads and environments that your structure is exposed to, to predicting the dynamic response and modifying the design to meet requirements, ATA can help.
Loads and Environments
ATA has extensive experience in defining the loads applied to a variety of aerospace structures. These include aerodynamic (quasi-static, gust and buffet) for both launch vehicles and aircraft, in flight and pad liftoff release, separation, parachute, plume impingement, on-orbit and docking, and reentry and landing loads. Derivation of these load cases involves a combination of advanced analytical tools and experience that comes from decades of working on a very wide variety of aerospace systems.
Dynamics Analysis Capabilities
ATA are industry leaders in modal analysis and forced response dynamics. We have supported the dynamic analysis of products ranging from electronics that must survive transportation and drop loads, to rocket engines subjected to random vibration and shock environments, to spacecraft and reusable launch vehicles that land on water or ground.
Our dynamics analysis capabilities include: normal modes analysis; transient, random, and sine vibration analysis; as well as shock response analysis. For structures undergoing high speed impacts that involve very complex dynamic contact situations including friction and nonlinear material behavior, ATA has significant experience in the use of explicit analysis methods. These solutions may also include nonlinear dynamic simulations of large angle motions, mechanisms, and crushable materials for shock attenuation.
ATA is also expert in the use of advanced methods related to the efficient solution of large scale dynamic models and specialized pre and postprocessing of dynamic analyses. These methods include substructuring of large models using superelements, component mode synthesis through the use of Craig-Bampton models, and development of Nastran DMAP alters for specialized analyses.
ATA has performed aeroelastic analyses of many aerospace systems; including static and dynamic aircraft loads, flutter, and divergence. We have analyzed fin components to full aircraft systems. ATA has used panel methods (such as ZAERO and Nastran) as well as more sophisticated CFD based computational aeroelastic techniques with experience in the subsonic, transonic, supersonic, and hypersonic flight regimes.
Coupled Loads Analysis
Coupled loads analysis is performed to understand how a payload, e.g., a satellite or spacecraft, interacts dynamically with the launch vehicle during launch and ascent. The loads and responses derived from this analysis are used to qualify the payload for launch aboard a given platform. ATA has extensive experience in load event definitions for different aspects of the launch event including static loads, dynamic loads, acoustic loads, aeroelastic loads, and engine startup and shutdown. We are experts in the use of component mode synthesis which is used to couple the payload model to the vehicle.
Mobility and Transportation
ATA staff have supported qualification of vehicles and cargo to withstand all types of mobility and transportation requirements for over 30 years. Road, rail, air, ship, and launch vehicle environments are used to evaluate vehicle design and payload packaging. Isolation may also be designed to protect vehicle components or payloads from environments. ATA has experience qualifying structures and payloads to specifications such as MIL-STD-810 for environmental requirements, MIL-HDBK-1791 for air transport, NASA-HDBK-7005 for dynamic environments, and many others.
A key factor in the success of any modal test and model correlation task is the development of a test-analysis model (TAM) to determine accelerometer and exciter locations and a mass matrix for orthogonality verification of test mode shapes. ATA has developed substantial capabilities for performing pretest analysis and accurately constructing a TAM, including different model reduction techniques, metrics for evaluating TAM performance, and algorithms for optimizing sensor and shaker locations. Many of these capabilities have been built into ATA’s IMAT software. Click here to learn more about this software.
Model Correlation and Updating
Post-test correlation and model updating are required to ensure that the model and subsequent analysis results are accurate. ATA has extensive experience in updating models to improve the correlation to test results for a wide variety of spacecraft, aircraft, missiles, electronics, and other structures. ATA has developed specialized methods for efficiently and effectively creating a test-verified model.
These methods have been captured in our commercial software, Attune. Click here for more information on this software.