Engineering topics
Babuska, Vit
Publications and source records attributed to Babuska, Vit.
Optimization of Fatigue Test Signal Compression Using the Wavelet Transform (Final Report)
This report summarizes Sandia National Laboratories (SNL) contribution to ATA Engineering, Inc's (ATA) project for the Naval Air Systems Command (NAVAIR), entitled "Optimization of Fatigue Test Signal Compression Using the Wavelet Transform." Sandia National Laboratories were a subcontractor to ATA. We were involved because this was a Small Business Technology Transfer (STTR) project that required ATA to partner with a national laboratory or academic institution. ATA selected SNL, and specifically the Environments Engineering Department (1557) because ATA has a long-standing working relationship with this department and the department staff have experience in environment definition, signal processing, fatigue testing protocols and traditional methods of generating inputs for accelerated fatigue testing.
Using Bispectral Analysis to Detect the Onset of Fatigue Damage in Randomly Excited Structures.
Abstract not provided.
Using Bispectral Analysis to Detect the Onset of Fatigue Damage in Randomly Excited Structures.
Abstract not provided.
Evaluating the use of Energy Response Spectra for Determining the Relative Severity of Machining Operations.
Abstract not provided.
On the Sensitivity of Energy Metrics to Failure in a Complex Structure.
Abstract not provided.
A Case Study for Integrating CompSim Credibility and Convolved UQ and Evidence Theory Results to Support Risk Informed Decision Making.
Abstract not provided.
WSEAT Shock Testing Margin Assessment Using Energy Spectra Final Report
Several programs at Sandia National Laboratories have adopted energy spectra as a metric to relate the severity of mechanical insults to structural capacity. The purpose being to gain insight into the system's capability, reliability, and to quantify the ultimate margin between the normal operating envelope and the likely system failure point -- a system margin assessment. The fundamental concern with the use of energy metrics was that the applicability domain and implementation details were not completely defined for many problems of interest. The goal of this WSEAT project was to examine that domain of applicability and work out the necessary implementation details. The goal of this project was to provide experimental validation for the energy spectra based methods in the context of margin assessment as they relate to shock environments. The extensive test results concluded that failure predictions using energy methods did not agree with failure predictions using S-N data. As a result, a modification to the energy methods was developed following the form of Basquin's equation to incorporate the power law exponent for fatigue damage. This update to the energy-based framework brings the energy based metrics into agreement with experimental data and historical S-N data.
A Case Study for Integrating Comp/Sim Credibility and Convolved UQ and Evidence Theory Results to Support Risk Informed Decision Making.
Abstract not provided.
Using Temporal Moments to Detect Interactions During Simultaneous Shock Testing of Multiple Components.
Abstract not provided.
ON THE SENSITIVITY OF ENERGY METRICS TO FAILURE TYPES IN A COMPLEX STRUCTURE.
Abstract not provided.
Evaluating the use of Energy Response Spectra for Determining the Relative Severity of Machining Operations.
Abstract not provided.
Using Temporal Moments to Detect Interactions During Simultaneous Shock Testing of Multiple Components.
Abstract not provided.
Substructure-based control of flexible structures
A decentralized procedure is presented for the design of controllers for flexible structures. Spatially significant components are created which approximate the response of a specific part of the complete structure. For each component, the controller and observer gain matrices which are used in a controller for the complete structure. The proposed method is illustrated on a model of NASA Langley's CSI testbed structure.