Acellent Technologies, Inc.

Irene Li

Fu-Kuo Chang

Xinlin Qing

Chang Zhang

Shawn J Beard

Jeffrey Dean Bergman

Hung Chi Chung

Patrick Joseph Pollock

Howard Hungchi Chung

Roger Huang

Bao Liu

Zengpin Yu

Lien Ouyang

Vishnuvardhan Janapati

Paul B Liu

Mark Pappakostas

Sang Jun Lee

Frank J Li

Methods and apparatuses for monitoring a first structure at least partially according to properties of a second structure. One such method comprises determining a first relationship between a first variable and a second variable, wherein the first variable represents sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure; determining a second relationship between a third variable and a fourth variable, wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure; and determining an estimate of damage to the first structure according to the first and second relationships.

Method and apparatus for less destructive evaluation and monitoring of a structure

A structural health monitoring apparatus is presented. According to an embodiment, the structural health monitoring apparatus comprises: a plurality of transducers configured for coupling to a structure, the structure comprising an outer structure surrounding and coupled to an inner structure, the transducers further configured for coupling to only the outer structure so as to transmit stress waves through the inner structure, and still further configured to receive the transmitted stress waves from the outer structure after they have passed through the inner structure; and an analyzer configured to detect damage within the inner structure according to the received transmitted stress waves from the outer structure.

System and method of diagnosing tube sensor integrity by analysis of excited stress waves

A structural health monitoring system comprises: a flexible substrate configured for attachment to a structure, the flexible substrate having a plurality of sensors affixed thereon. The flexible substrate comprises a first portion configured for attachment to the structure, a second portion extending in continuous manner from the first portion, and a third portion extending in continuous manner from the second portion and being configured for attachment to the structure. The second portion includes a first section extending in continuous manner from the first portion, a second section connected between the first section and the third portion and having an edge extending in a direction different from an edge of the first section.

Stretchable sensor layer

Placement of structural health monitoring sensors within a coupled bearing assembly. An exemplary structural health monitoring system comprises first and second bearings configured for rotatable positioning along a structure, and a spacer positioned between the first and second bearings. The first and second bearings are placed against opposing sides of the spacer, and have a preload force engaging the respective first and second bearings against the opposing sides of the spacer. A plurality of sensors are coupled to the spacer so as to be positioned between the spacer and at least one of the first and second bearings, the sensors further coupled to at least one of the first and second bearings so as to be configured to monitor a structural health of the at least one of the first and second bearings.

System and method for monitoring the structural health of coupled bearings

A structural health monitoring system capable of maintaining electrical contact with sensors affixed to a rotating structure. One such structural health monitoring system comprises a rotatable structure, a plurality of sensors each affixed to the rotatable structure, and an interface. The interface has an inner housing and an outer housing, and maintains a plurality of individual electrical connections, each of the individual electrical connections being an electrical connection between one of the sensors and an electrical contact maintained on the outer housing, the electrical connections configured to be maintained during rotation of the structure. The inner housing is affixed to the structure and the outer housing is rotationally coupled to the inner housing, so that the inner housing is free to rotate with respect to the outer housing during rotation of the structure and the sensors, while maintaining the electrical connections.

System and method for monitoring the structural health of rotating elements

A self-sufficient structural health monitoring system that can monitor a structure without need for external power input. Embodiments of the invention provide a structural health monitoring system with a power supply integrated within, so that the system relies on itself for operational power. Systems with such an on-board electrical power source, independent of an external power source (and in particular, independent of the power system(s) of the structure being monitored), are much more self-contained and self-sufficient.

Structural health monitoring system having integrated power supply

A structural health monitoring system using ASICs for signal transmission, reception, and analysis. Incorporating structural health monitoring functionality into one or more ASICs provides a durable yet small, lightweight, low cost, and portable system that can be deployed and operated in field conditions. Such systems provide significant advantages, especially in applications such as armor structures.

Integrated circuit system for controlling structural health monitoring processes

Sensors affixed to various such structures, where the sensors can withstand, remain affixed, and operate while undergoing both cryogenic temperatures and high vibrations. In particular, piezoelectric single crystal transducers are utilized, and these sensors are coupled to the structure via a low temperature, heat cured epoxy. This allows the transducers to monitor the structure while the engine is operating, even despite the harsh operating conditions. Aspects of the invention thus allow for real time monitoring and analysis of structures that operate in conditions that previously did not permit such analysis. A further aspect of the invention relates to use of piezoelectric single crystal transducers. In particular, use of such transducers allows the same elements to be used as both sensors and actuators.

Method and apparatus for conducting structural health monitoring in a cryogenic, high vibration environment

Integrated circuit system for controlling structural health monitoring processes and applications therefor

Storage of information, such as baseline information and structure ID, in a memory that is mounted on the structure, rather than inside the diagnosis hardware. This allows for faster and more convenient information retrieval. In particular, this approach allows for a more modular system in which different diagnosis hardware or other analyzers can be simply plugged into a structure's sensor network, whereupon they can quickly download any desired structure-specific information (e.g., baseline information, structure ID, and other useful information) from the on-structure memory.

Structural health monitoring system having memory on structure

Methods and apparatuses for detecting fastener loosening. Sensors query a structure at a baseline value of an environment variable, such as temperature, and this baseline signal is stored for later use. Subsequently, users can query the structure remotely and at any time, and the signals from these queries are compared to the stored baseline signal. In some embodiments, an index is calculated, and the system determines that one or more fasteners have come loose if the calculated index exceeds a predetermined threshold value. It is desirable to select a time window within which the query signal is most sensitive to fastener loosening but least sensitive to variations in the environment variable. Accordingly, embodiments of the invention include methods and apparatuses for determining an optimal time window for use in calculating the above described index.

Method and apparatus for loosening of fasteners on structures

Detection of damage in armor structures, using networks of piezoelectric transducers. In particular, piezoelectric transducers can be placed at various points on the armor structure, effectively creating a number of paths between pairs of transducers. Each of these paths can be queried by transmitting an ultrasonic stress wave from one transducer to the other, and analyzing changes in the stress wave. The signal from the received stress wave can be time gated to remove crosstalk, and the resulting time gated signal can be analyzed for characteristics of damage. For instance, if the time gated signal is sufficiently attenuated, it can be determined that the armor structure has sustained damage to at least that region traversed by this particular path.

Method and apparatus for detecting damage in armor structures

A method useful in structural health monitoring (SHM) systems for detecting damages in metal structures includes extracting the zero-order symmetric and anti-symmetric mode signal components from each of a plurality of current sensor signals of an array of transducers mounted on the structure, matching the extracted signal components with corresponding signal components of a plurality of baseline sensor signals previously detected in the structure, computing respective indices Iand Ifor each of the matched extracted current and baseline signal components based on respective signal energies thereof, and determining the presence of a damage in the structure if either of the indices Iand Iof a plurality of neighboring sensor paths of the structure is greater than a selected threshold value.

Detecting damage in metal structures with structural health monitoring systems

A method for both detecting and analyzing a change in the loading condition of a structure. A flexible substrate is employed, in which a distributed network of sensors is built. This substrate is either affixed to the surface of the structure, or built within it, so as to be able to detect propagating stress waves. After load change is detected, the resulting sensor signals are analyzed to determine the location, severity, and/or any characteristic frequencies of the load change. This information is then used to determine an appropriate response.

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Stanford, CA, United States of America

Irene Li