The Boeing Company

Theboeing Company

Joseph D Schaefer

Brian P Justusson

Hong Hue Tat

Yuan-Jye Wu

Anne Kao

Roy Martin Gagnon

Mary J Mathews

Rongzhong Li

Victor P Pauca

Dinu Tandareanu

Tyler M Holmes

John A Mittleider

Haozhong Gu

Scott Hutchinson Gardner

Brian Scott Kasperson

Bryan W Lilley

Matthew Jeffrey Molitor

Matthew G Pike

David R Barbee

James W Edwards

Mary J Matthews

Scott H Gardner

A method for determining fatigue properties of a structure includes mounting the structure in a load frame. The structure has a crack with a crack size. The method includes applying repeatedly an adjustable stimulus to the structure over multiple cycles. The adjustable stimulus is an adjustable load or an adjustable displacement applied to the structure. The method further includes storing the crack size at a start of the cycles, measuring a response of the structure subjected to the adjustable stimulus in each cycle, updating the crack size based on the response in each cycle, and updating the adjustable stimulus in each cycle. The adjustable stimulus as updated maintains a strain energy release rate approximately constant based on the crack size. The method includes calculating a growth rate of a crack propagation in the structure based on the response in each cycle, and storing the growth rate in a file.

Determination of structure fatigue properties

A tension load fixture for applying tension or loading forces to a specimen comprises a pair of tension arms and an imaging device. The pair of tension arms are configured to releasably couple to opposite end regions of a specimen and to apply tension or loading forces to the specimen. The specimen is configured to be positioned between the pair of tension arms and defines a notch between the opposite end regions of the specimen. The notch extends from a side of the specimen to a middle region of the specimen. The imaging device is configured to capture one or more images of the middle region of the specimen and is configured to rotate about a central axis of the tension load fixture that is proximate to the middle region of the specimen to facilitate generation of a three-dimensional image of the middle region of the specimen as the specimen is subjected to tension or loading forces.

Tension load fixture and method for evaluating fracture behavior of a composite material

A computer is configured to generate a computer model predicting the progressive creation, density, and spacing of a plurality of cracks in a filler material, such as a 'noodle,' for example, disposed at a connection interface between a load-bearing composite structural component, such as a stringer or a spar, for example, and the structural framework of a vehicle on which those structural components are utilized.

Method for determining noodle and interface residual stresses and properties under hygrothermal-mechanical loadings

An example method includes determining, by a computing system, a dry thickness of a fabric preform. The method also includes determining, by the computing system, a debulked thickness of the fabric preform using the dry thickness of the fabric preform. In addition, the method includes determining, by the computing system, a stitch tension using the dry thickness of the fabric preform and the debulked thickness of the fabric preform. And the method includes causing, by the computing system, a stitching machine to apply a through-the-thickness stitch having the stitch tension to the fabric preform.

Manufacturing processes for improved mechanical performance of stitched composites

A method, apparatus, and system for managing a composite structure. A set of component models is created for a set of components in the composite structure. A set of embedded reinforcement element models is placed within the set of component models for the set of components in the composite structure to form a composite structure model for the composite structure. The set of embedded reinforcement element models is for a set of embedded reinforcements embedded within the set of components in the composite structure. A structural analysis of the composite structure is performed using the composite structure model formed by the set of component models and the set of embedded reinforcement element models, wherein the set of embedded reinforcement element models enables modeling at least one of a deformation or a failure of embedded reinforcements.

Reinforced composite structure analysis system

A method includes obtaining failure initiation characteristics of a bonding layer of one or more bonded structures and determining, based on the failure initiation characteristics, a first characteristic dimension for each analysis element of a first portion of a finite element analysis model. The method includes obtaining failure propagation characteristics of the bonding layer and determining, based on the failure propagation characteristics, a second characteristic dimension for each analysis element of a second portion of the model. The method includes assigning a first set of material parameters to analysis elements of the first portion of the model and assigning a second set of material parameters to analysis elements of the second portion of the model. The method includes evaluating failure modes of the one or more bonded structures based on a solution to the model, the first set of material parameters, and the second set of material parameters.

System and method for predicting failure initiation and propagation in bonded structures

A load frame for applying a tensile load to a test sample during a test or measurement includes a first gripper for gripping a first end of the test sample, a second gripper for gripping a second end of the test sample, and a tensioner for applying the tensile load to the test sample. The load frame further includes a first end tube that encircles the first gripper, a second end tube that encircles the second gripper, and a center tube that encircles a mid-portion of the test sample during the test or measurement. A system such as a wave-generating system may be used to measure the test sample through the center tube during a test or measurement.

Self contained load frame for in-situ inspection

A compression test fixture including a first specimen engagement member having a first channel, the first channel having a first depth; a second specimen engagement member having a second channel having a second depth that is different than the first depth; and at least one coupling member engaged to both the first specimen engagement member and the second specimen engagement member such that a gap is defined between the first specimen engagement member and the second specimen engagement member, where the first channel and the second channel support the test specimen within the gap such that at least one opposing major surface of the test specimen is visible within the gap.

Compression test fixture and method therefor

An apparatus comprises an acoustic sensing system and an analyzer module. The acoustic sensing system is positioned relative to an object, wherein the acoustic sensing system detects acoustic emissions and generates acoustic waveform data for the acoustic emissions detected. The analyzer module is implemented in a computer system that receives load data and the acoustic waveform data for the object, generates a plurality of frequency distribution functions using the acoustic waveform data, and generates a frequency distribution function time evolution image containing a plurality of points of each of the plurality of frequency distribution functions.

Method and apparatus for acoustic emissions testing

A holder for attaching an acoustic emission sensor to a non-metallic and non-magnetic material has a tubular body with a closed top end and an open bottom end through which the sensor is insertable into the tubular body. The closed top end has a plurality of unitary flexible flaps angularly extending inwardly from an inner surface of the enclosed top end. An inner surface of the tubular body has a plurality of spacers extending radially inward proximate the bottom end of the tubular body. The unitary flexible flaps and the spacers fix the sensor within the tubular body. The tubular body may also have a plurality of capture tabs extending outwardly from an exterior surface thereof proximate the open bottom end that are slidably and removably engageable with an engagement keyway in a retainer bracket that is affixed to a non-metallic and non-magnetic material.

Acoustic emission sensor holder

A method and apparatus for analyzing an object using acoustic emissions. Load data is received for the object. Acoustic waveform data is received for the object from an acoustic sensing system. The acoustic waveform data represents acoustic emissions emanating from the object and is detected using the acoustic sensing system. A plurality of bins is created for the load data. A plurality of frequency distribution functions is generated for the plurality of bins using the acoustic waveform data. A set of learning algorithms is applied to the plurality of frequency distribution functions and the acoustic waveform data to generate an output that allows an operator to more easily and quickly assess a structural integrity of the object.

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St. Louis, MO, United States of America

Joseph D Schaefer