Specialised Software Tools

ACS SASSI

It is a highly specialized, Windows XP, user-friendly, finite element computer code for performing efficiently nonlinear 3D dynamic soil-structure interaction (SSI) analyses for complex geometry foundations subjected to spatially varying incoherent motions or multiple support seismic excitations. ACS SASSI that is a modern software coded using advanced features of VC++ and Fortran90 languages, provides a set of totally new engineering capabilities for SSI analysis in comparison with the original SASSI developed by Professor J. Lysmer and co-workers at University of California at Berkeley.

Brief Technical Description

Related Paper on Westinghouse AP1000 Nuclear Island
Related Paper by US NRC Staff

Presentation Slides

Animation(38MB): Acceleration Response of An Embedded Nuclear Reactor Building
Animation(1.5MB): Seismic Pressure Fluctuation for Y-Input on An Embedded Foundation
Animation(11MB): AP1000-Based Stick Coherent Displacement wrt to Free-Field Input
Animation(11MB): AP1000-Based Stick Incoherent Displacement wrt to Free-Field Input

ProCORFA

It is a highly specialized, Windows XP, user-friendly computer code for performing probabilistic life, and reliability prediction for aircraft and vehicle structures subjected to progressive stochastic corrosion-fatigue damage including the effects of maintenance activities. In addition to stochastic modeling and risk prediction capabilities, ProCORFA includes a stochastic cost modeling module. ProCORFA has a fully integrated software interface with the USAF AFGROW code for fatigue crack propagation computation. ProCORFA package also includes an interface with ANSYS code that is programmed in ANSYS ADPL language. ProCORFA is being developed in collaboration with STI Technologies and Cornell University. ProCORFA is programmed in Visual Basic and Fortran90.

Description

Slide Presentation

Related Paper

Animated Demo

GEOMIS

It is a highly specialized computer code for performing extremely fast and accurate mistuning analysis of bladed disk assemblies of gas turbine engines or power turbines. GEOMIS has the unique capability of considering the blade geometry mistuning effects due inherent manufacturing deviations on turbine blade-disk system vibration. GEOMIS performs geometry mistuning analysis using an efficient reduced-order modeling (ROM) based on “iterative eigensubpace projection” (IES) and “stochastic perturbation matrix” (SPM) approach.

GEOMIS is intimately interfaced with the ANSYS code that is used for bladed-disk system finite element modeling. Both the IES and SPM ROMs were developed by GP Technologies under its own internal resources. No publication is available for IES, and only a single publication is available for SPM (but only for mistuning analysis directly in the complex frequency domain, not in the modal domain - click on "related paper" link to see the paper on SPM). Both IES and SPM are very accurate for both frequency and geometry bladed-disk mistuning predictions. Both IES and SPM do not need any preliminary sector frequency calculations that provide a significant relief to the structure analyst.

Also, both IES and SPM do not require any preliminary work for identification and separation of system modes in isolated mode families which many times is an almost an impossible task for the analyst, especially for frequency ranges in which mistuned mode frequencies of different mode families interfere in a unknow, random pattern. Under "Animated Demo" selection a prototype MATLAB software version is shown. The full capability version of the GEOMIS code is programmed in VC++ and Fortran90.

Slide Presentation

Related Paper

Animated Demo

BladeHCF

It is a highly integrated, graphical computational environment for preforming probabilistic forced response and failure risk assessment for turbine engine bladed-disk assemblies that are subjected to high-cycle fatigue (HCF). The HCF damage occurs due to the structural vibration of these assemblies due to steady and unsteady gas pressure fluctuations on rotating blades. BladeHCF is a user-friendly, object-oriented, prototype software developed under the MATLAB/SIMULINK environment that can be easily adapted to various advanced turbine design, analysis and risk prediction applications.

The BladeHCF structure is modular and incorporates a number of graphical computational modules. BladeHCF uses ANSYS finite element code for steady and unsteady structural stress analysis. Aero-forcing is defined deterministically or probabilistically using simple engineering calculations based on aeromechanical tests. Brief animated demos for different graphical computational modules can be seen by clicking on Blade Geometry Variation module, Preliminary Deterministic System Force Response module, Probabilistic System Forced Response module, and Blade HCF Risk Prediction module.

It should be noted that GEOMIS code (please see above) that provides unique computational capabilities using reduced-order modeling for performing efficient and accurate geometry-based mistuning analyses of bladed-disk assemblies is included as a part of BladeHCF, namely within the Probabilistic System Forced Response module. Blade HCF risks are predicted using the probabilistic Goodman diagram failure criteria. Stochastic modeling uncertainty effects on probabilistic blade stresses due to small sample size effects, i.e. limited number of measured blades/rotors are included and used to define HCF risk variation bounds. BladeHCF also includes algorithms for aggregation of various information sources coming from computational blade stress/strain predictions, available test data, i.e. strain-gage and/or rig test data, and expert opinions.

Related Paper

Animated Demo

BLASTEX

It is a set of five highly specialized, Windows XP interactive, easy-to-use computer programs for a rapid evaluation of typical explosion blast effects on buildings, vehicles and surrounding people. The five computer codes are designed to be used by non-experts in blast physics and non-engineers. An earlier version of BLASTEX codes was distributed at a number of police departments, government agencies and national labs. The distribution of the BLASTEX package is limited to the US government agencies or institutions and national labs.

Description

ProMACOR

It is a highly specialized, Windows XP interactive, user-friendly computer code for performing probabilistic life, and reliability prediction for gas turbine engine blades subjected to low-cycle fatigue (LCF) and high-cycle fatigue (HCF) damage including the uncertainties associated with periodic maintenance inspections. For computing LCF-HCF interaction effects, ProMACOR uses advanced nonlinear damage models. Effects of random foreign object impacts on blade can also be included using stochastic simulation. ProMACOR is being developed together with STI Technologies. ProMACOR is not available as an integrated commercial package for sale. We are interested to work with gas turbine engine manufacturers to develop in-house customized versions for them.

Related Paper

StoFIS

It is a collection of software modules and libraries that can be integrated for performing in-flight risk-based fault diagnostics and prognostics in aircraft jet engines. To capture the complex functional stochastic relationships between different engine performance parameters or statistical features of vibration measurements, StoFIS combines advanced stochastic modeling with artificial intelligence tools for engine health risk management. StoFIS is an adaptive stochastic-fuzzy network-based inference and prediction system. Although, the software is based on complex stochastic approximation and prediction techniques, its output is simple, easy to interpret and highly practical. The user views probabilistic predictions interms of simple reliability metrics that can be easily interpreted for maintenance decisions. StoFIS has been developed together with STI Technologies. StoFIS is not available for sale as an integrated commercial package. We are interested to work with aircraft and helicopter engine manufacturers to develop refined in-house customized versions for them.

Slide Presentation

Related Paper

StoOPT

It is a collection of powerful computational toolboxes for complex stochastic-optimization problems involving large number of uncertain variables and/or high nonlinear noisy responses. The StoOPT package uses advanced dynamic simulation based on multilevel Markov Chain Monte Carlo algorithms with gradient hints coming from moving particle inertia. Based on extensive testing of convergence robustness for finding the global extrema, the StoOPT algorithms outperform all other reputed stochastic-optimization algorithms. To take full advantage of these robust algorithms in our reliability-based design optimization analyses, we use these algorithms in conjunction with advanced response surface modeling techniques based on stochastic field models integrated in our StoRES software. StoOPT is not available for sale as an integrated commercial software package. We are interested to work with our industry customers to developed in-house customized implementations for them.

StoRES

It is a collection of computational toolboxes for approximating complex system response surfaces involving a large number of uncertain variables and/or high nonlinear noisy responses. The StoRES package uses advanced stochastic field models for response surface modeling including one-level, two-level and three-level hierarchical stochastic approximation models, MCMC simulation-based approximation models, statistical and fuzzy clustering-based interpolation models, (non-Gaussian) translation field models and spatial stochastic-interpolation models including Gaussian krigging and radial-basis functions. The StoRES approximation models applied in conjunction with the StoOPT simulation-based stochastic-optimization models provide a unique set of toolboxes for rapidly solving reliability-design optimization problems. Based on numerical investigations done in-house and in collaboration with University of Iowa, we noticed that our StoOPT-StoRES suite of algorithms can reduce the number of computational mechanics analyses (function evaluations), such as finite element analyses or computational fluid dynamics analyses, needed for performing a reliability-based design optimization by 4 to 8 times. StoOPT is not available for sale as an integrated commercial software package. We are interested to work with our industry customers to developed in-house customized implementations for them.

StoUNC

It is a collection of computational toolboxes based on new theoretical concepts that were developed in-house for incorporating epistemic uncertainties in probabilistic structural mechanics analyses. The new concepts are being built on the imprecise probability theory that addresses practical, real situations when available statistical data is limited or very limited. StoUNC is not available for sale as an integrated commercial software package. We are interested to work with our industry customers to developed in-house customized implementations for them.