The Boeing Company

David W Twigg

Mostafa Rassaian

Anapathur V Ramesh

Tilak C Sharma

Kishor S Trivedi

Yun Liu

Dazhi Wang

Le P Nguyen

Kevin Nicholas King

Jung-Chuan Lee

Larry R Schultz

Jeffrey Ko

Michael A Millette

A safety-analysis system for a complex system such as an aircraft includes a system modeler and model-analysis system. The system modeler is configured to receive component fault-based models of respective components of which a system is composed, such as from a library of component fault-based models in storage. The component fault-based models include transfer functions expressed as fault trees each of which describes behavior of a respective component in an event of a failure of the respective component or of an input to the component. The system modeler is also configured to assemble the component fault-based models into a system fault-based model of the system, with the system fault-based model including a transfer function expressed as an assembly of the fault trees of the component fault-based models. The model-analysis system, then, is configured to perform a safety analysis using the system fault-based model.

Safety analysis of a complex system using component-oriented fault trees

A computer-based method for determining a probability that no path exists from a starting node to a target node within a network of nodes and directional links between pairs of nodes. The nodes and directional links form paths of a reliability graph and the method is performed using a computer coupled to a database. The method includes selecting a set of paths between the starting node and the target node that have been determined to be reliable, calculating a reliability of the union of the selected path sets, setting an upper bound for unreliability of the set of all paths, selecting a set of minimal cutsets from all cutsets that lie between the starting node and the target node, calculating the probability of the union of the minimal cutsets, and setting a lower bound for the unreliability of the set of all cutsets.

Reliability estimation methods for large networked systems

A cross-spectral correlation function of a structure may be determined by providing a finite element model of the structure having a plurality of elements each having a centroid. A plurality of composite centroids may be determined wherein each one of the composite centroids is based on at least one of the elements. The cross-spectral correlation function between at least one pair of the elements in the finite element model may be assigned to be the cross-spectral correlation function of the composite centroids that include the centroids of the elements. If the pair of elements is included in the same composite centroid, then the cross-spectral correlation function between the elements is assigned to be the autocorrelation function of the composite centroid that includes the pair of elements.

Acoustic modeling method

A computer-based method for determining a probability that no path exists from a specified starting node to a specified target node within a network of nodes and directional links between pairs of nodes is described. The nodes and directional links form paths of a reliability graph and the method is performed using a computer coupled to a database that includes data relating to the nodes and the directional links The method includes selecting a set of paths, from the set of all paths, between the starting node and the target node that have been determined to be reliable, calculating a reliability of the union of the selected path sets, setting an upper bound for the unreliability of the set of all paths, based on the calculated reliability, selecting a set of minimal cutsets from all such cutsets that lie between the starting node and the target node, calculating the probability of the union of the minimal cutsets, and setting a lower bound for the unreliability of the set of all cutsets.

The invention discloses differing embodiments of finite element modeling methods utilizing mass distribution to model an object. In one embodiment, the finite element model of the object may be partitioned into sub-models. A determination may be made as to which elements in the finite element model are structural and as to which elements in the finite element model are non-structural. Mass properties for both the structural and non-structural elements in each sub-model may be determined. The significant non-structural masses within each sub-model may be selected and added to the finite element model. The remaining insignificant, non-structural masses may be incorporated onto the structural masses by scaling densities of the structural masses. The scaled structural masses may then be added to the finite element model. In other embodiments, objects are provided which were modeled utilizing finite element models under the invention.

Finite element modeling method utilizing mass distribution

Analyzing system malfunction data and associated direct and indirect effects in a collaborative tool to determine relationships between the effects and the system malfunction information. System malfunction cases and other data are received and stored. A user may view and/or modify the system malfunction data. The data may be presented in a relational structure. Each system malfunction case is linked to one or more direct effects, and each direct effect is linked to one or more indirect effects.

Collaborative web-based airplane level failure effects analysis tool

Techniques for creating an acoustic model from a finite element mode include strategically partitioning elements of the finite element model into sets, forming composite centroids from the partitioned elements and then calculating the spatial distances between the composite centroids so that an acoustic model can be created using a tiny portion of the computational power otherwise required. By further constraining the composite model to conform to an M-by-N array, object-oriented code can be used.

Object oriented acoustic modeling tools and methods

A computer implemented method, apparatus, and computer usable program code for analyzing durability of electronic components. A finite element model for the chassis is created. A set of finite element models for a set of printed wiring assemblies are created, wherein the printed wiring assemblies are for use with chassis and include the electronic components. The finite element model for the chassis is combined with the set of finite element models to form a combined finite element model. A finite element analysis of the combined finite element model is performed to form results. The combined model results are transferred to the printed wiring board models. Using the transferred results, stresses and strains are calculated for individual solder joints/leads. A fatigue analysis is performed for the electronic components in the set of printed wiring assemblies based on these stresses and strains, using the results to identify the durability of the electronic components.

Method and apparatus for integrated hierarchical electronics analysis

A system for evaluating time requirements for performing maintenance on a maintenance object. One or more processors and memory are operable to provide a form on which a user describes a maintenance task. The described task is made available for maintenance time analysis as at least one of the following: a main task, a subtask of another main task, and an elementary operation. The user is allowed to combine a plurality of described tasks into one or more hierarchies designated by the user. This system provides flexibility to evaluate maintenance task times regardless of whether a level of detail and/or design maturity is minimal or complete.

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Federal Way, WA, United States of America

David W Twigg