Testing system and method for applying loads to a test specimen
Inventors
Saari, Byron John • Kerr, Robert Brian
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10551286-B2
Publication Date
2020-02-04
Expiration Date
Abstract
An aspect of the invention is a testing system for applying loads to a test specimen. The testing system includes the actuator and the first support portion supporting the actuator. The actuator is configured to support a first end of the test specimen, while a second support portion configured to support a second end of the test specimen. In various embodiments, combination of sensors that can include displacement sensor and/or accelerometer(s) provide associated output signals that are received by a displacement compensator that is configured to provide a displacement output signal indicative of differential displacement between first end and the second end of the test specimen.
Core Innovation
A testing system for applying loads to a test specimen includes an actuator, a test frame with a first support portion and a second support portion coupled by columns, and sensors for displacement-related measurements at opposite specimen ends. The first support portion supports the actuator and is configured to support a first end of the test specimen, while the second support portion is configured to support a second end of the test specimen. A first sensor provides a first output signal indicative of displacement of the first end of the test specimen.
An acceleration sensor measures acceleration of the first support portion or the second end of the test specimen and provides a second output signal indicative of the measured acceleration. A displacement compensator receives the first output signal and the second output signal and provides a displacement output signal indicative of differential displacement between the first end and the second end of the test specimen. The displacement compensator combines displacement measurement with acceleration measurement to obtain differential displacement.
In embodiments, differential displacement is obtained using acceleration-based processing, including forming a difference acceleration signal and double integrating to provide the displacement output signal, or double integrating accelerations at both ends to obtain displacement signals and then subtracting. Alternative compensator arrangements include using an accelerometer mounted on the crosshead or support to avoid a moving accelerometer on the first end, while providing compensation for differential displacement. A related displacement correction approach supports a second end in at least a substantially fixed position and obtains an output signal indicative of differential displacement between the second end and the first end using measured acceleration of the second end and measured acceleration or displacement of the first end.
Claims Coverage
The provided independent claims cover three aspects: a testing system that generates differential displacement using a displacement sensor plus an acceleration sensor and a displacement compensator; a testing system using first and second specimen grips with a force transducer and first and second accelerometers; and a method of providing displacement correction by supporting one end substantially fixed and obtaining an output signal indicative of differential displacement. Three inventive features are identified.
Differential-displacement compensated testing system using actuator, frame supports, displacement sensor, and acceleration sensor
A testing system comprising an actuator; a test frame having a first support portion and a second support portion coupled by columns, the first support portion supporting the actuator with the actuator configured to support a first end of the test specimen and the second support portion configured to support a second end of the test specimen; a first sensor providing a first output signal indicative of displacement of the first end; an acceleration sensor measuring acceleration of the first support portion or the second end and providing a second output signal indicative of the measured acceleration; and a displacement compensator receiving the first and second output signals and providing a displacement output signal indicative of differential displacement between the first end and the second end.
Specimen-grip testing system with force transducer, two accelerometers, and differential displacement compensator
A testing system comprising a first specimen grip engaging a first end of the test specimen and a second specimen grip engaging a second end of the test specimen; a force transducer configured to support the second specimen grip and a base configured to support the force transducer; an actuator supported by the base and configured to support the first specimen grip; a first accelerometer configured to measure acceleration of the first end when mounted in the first specimen grip and provide a first acceleration output signal; a second accelerometer configured to measure acceleration of the second end when mounted in the second specimen grip and provide a second acceleration output signal; and a displacement compensator receiving the first and second acceleration output signals and providing a displacement output signal indicative of differential displacement between the first end and the second end.
Displacement correction method using substantially fixed second end and differential displacement output
A method of providing displacement correction in a testing machine having an actuator applying force or displacement to a test specimen, comprising supporting a second end of the test specimen in at least a substantially fixed position; applying a force to a first end of the test specimen; measuring acceleration of the second end; measuring acceleration or displacement of the first end; and obtaining an output signal indicative of differential displacement between the second end and the first end using the measured acceleration of the second end and the measured acceleration or displacement of the first end.
Across the independent claims, the core coverage lies in generating a displacement output indicative of differential displacement between a first end and a second end by combining displacement or acceleration information from the first end with measured acceleration at the second end or associated support. The compensator-based differential displacement output is emphasized in both testing-system claims, and a corresponding measurement-to-differential-displacement correction method is covered in the method claim.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?