Dry Contact Ultrasonic In-Plane Modulus Testing
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Solution Overview
Problem
Current in-plane modulus testing of composites is destructive, and existing non-destructive evaluation methods face challenges with couplant contamination and sensitivity issues, particularly for high-performance materials like ceramic composites and metals, especially at elevated temperatures.
Innovation Solution
A dry contact ultrasonic testing method using low-frequency longitudinal wave transducers with a delay line and a polymer membrane couplant, allowing for non-destructive evaluation of specimens without liquid couplants, enabling testing at elevated temperatures and reducing contamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If liquid couplant is used for ultrasonic testing, then ultrasonic signal transmission is improved, but specimen contamination occurs
Solution Approach 1:
A thin membrane serves as an intermediary between the ultrasonic transducer and the specimen, enabling ultrasonic energy transmission while preventing liquid couplant from contacting and contaminating the specimen surface
Solution Approach 2:
The patent replaces the traditional liquid couplant-based mechanical coupling system with a solid membrane-based dry contact system, eliminating the need for liquid couplant while maintaining ultrasonic transmission capability
2Object-affected harmful factors
If water immersion is used for ultrasonic testing, then couplant-free condition is achieved, but testing at elevated temperature is limited
Solution Approach 1:
The thin membrane acts as a thermal and mechanical intermediary that allows the specimen to be tested at elevated temperatures without requiring water immersion, enabling high-temperature ultrasonic testing while maintaining dry contact conditions
3Object-affected harmful factors
If advanced dry contact tools such as lasers are used, then couplant-free ultrasonic testing is achieved, but sensitivity in ultrasonic signals deteriorates
Solution Approach 1:
A thin flexible membrane is used as the dry contact interface between the transducer and specimen, providing sufficient ultrasonic signal transmission sensitivity while maintaining couplant-free testing conditions, unlike other advanced dry contact methods such as lasers
4Measurement precision
If mechanical testing with tensile test machine is used, then in-plane modulus measurement is achieved, but specimen destruction occurs
Solution Approach 1:
The patent replaces the destructive mechanical tensile testing system with a non-destructive ultrasonic testing system that uses acoustic wave propagation to measure in-plane modulus, preserving specimen integrity while providing accurate material property measurement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for accurate, non-destructive in-plane modulus measurement of thin composite specimens at elevated temperatures with high sensitivity, reducing testing time and costs, and maintaining specimen integrity for further processing.
Implementation Method 1
a first ultrasonic longitudinal wave transducer configured to be coupled to a first contact point of a specimen to be tested; a second ultrasonic longitudinal wave transducer configured to be coupled to a second contact point of the specimen
Implementation Method 2
the first ultrasonic longitudinal wave transducer is configured to transmit a guided wave into the specimen, and the second ultrasonic longitudinal wave transducer is configured to receive the guided wave from the first ultrasonic longitudinal wave transducer
Implementation Method 3
a delay line between at least one of the first ultrasonic longitudinal wave transducer and the first contact point and the second ultrasonic longitudinal wave transducer and the second contact point
Data Source
AI summary
An apparatus for performing nondestructive evaluation of a specimen comprises a first ultrasonic longitudinal wave transducer configured to be coupled to a first edge of a specimen to be tested; a second ultrasonic longitudinal wave transducer configured to be coupled to the first side of the specimen at a predetermined distance from the first ultrasonic shear wave transducer, wherein the first ultrasonic longitudinal wave transducer is configured to transmit a guided wave into the specimen, and the second ultrasonic longitudinal wave transducer is configured to receive the guided wave from the first ultrasonic longitudinal wave transducer. The first ultrasonic longitudinal wave transducer and the second ultrasonic longitudinal wave transducer are low frequency longitudinal transducers that are capable of operating at or below 0.5 MHz (500 KHz). A membrane may be used as the couplant between the transducers and the specimen.