US 5,165,270 A · Non-destructive materials testing apparatus and technique for use in the field

Abstract

The present invention features an apparatus and method for impact-echo testing of structures in situ, in the field. The impact-echo testing method provides a non-invasive, non-destructive way of determining the defects in the structure. The method is both uniform and reliable, the test procedure being substantially identical every time. The apparatus of the invention comprises a portable, hand-held unit having a plurality of impactors disposed therein. The plurality of impactors comprise a number of differently weighted spheres that are each designed to impart a different impact energy into the structure to be tested. Each sphere is disposed on a distal end of a spring-steel rod. A particular weighted sphere is chosen by a selector disposed on the testing unit. The sphere is withdrawn from the rest position by a pair of jaws to a given height above the structure. At a predetermined release point, the sphere is released, causing it to impact the structure with a specific duration and impart a given energy thereto. The impact produces stress waves that are reflected from the internal flaws and external surfaces of the structure. The reflected waves are detected by a transducer that converts the stress waves into an electrical signal (displacement waveform). The waveform is then processed to provide an amplitude spectrum, and in the case of plates, a reflection spectrum. For plates, the reflection spectrum can be interpreted by a neural network provides results that are indicative of either the thickness of the structure or of the defects disposed therein.

Claims26

Dependent claims

An impact device for generating impact-echo signals in structures, comprising:

a triggering mechanism for initiating an impact sequence of events in the echo-impact testing of a structure;
a transducer operatively connected to said triggering mechanism for detecting reflected impact signals traveling through said structure being tested, and generating an electrical signal in response thereto;
an impact mechanism connected to said triggering mechanism for introducing a selectable duration impact for generating stress waves for propagation within said test structure, said generated stress waves being frequency-dependent upon the duration of the selected impact, and said frequency being related to thickness of said structure, whereby the selection of said impact duration provides a means by which a structure and its flaws can be measured;
and
activating means operatively connected to said impact mechanism, said transducer, and said trigger mechanism for activating said transducer in operative sequence with the introduction of the impact signal in said test structure.

2 more elements

Dependencies are inferred from the claim text.

Non-destructive materials testing apparatus and technique for use in the field

Life of this patent

Non-destructive materials testing apparatus and technique for use in the field

Life of this patent

Abstract

Claims26