1. Scope

1.1 This practice establishes two procedures for ultrasonic testing (UT) of flat panel composites and flat sandwich core panels (parallel surfaces). Typical as-fabricated lay-ups include uniaxial, cross ply and angle ply laminates; as well as honeycomb sandwich core materials. These procedures can be used throughout the life cycle of the materials; product and process design optimization, on line process control, after manufacture inspection, and in service inspection. Contact methods such as angle-beam techniques using shear waves, or surface-beam techniques using Lamb waves, are not discussed.

1.2 Ultrasonic testing is a common sub surface method for detection of laminar oriented discontinuities. Two techniques can be considered based on panel surface accessibility; pulse echo for one sided and through transmission (bubblers/squirters) for two sided. As used in this practice, both require the use of a pulsed straight-beam ultrasonic longitudinal wave followed by observing indications of either the reflected (pulse-echo) or received (through transmission) wave. The general types of anomalies detected by both techniques include foreign materials, delamination, disbond/un-bond, fiber de-bonding, inclusions, porosity, and voids.

1.3 This practice provides two ultrasonic test procedures. Each has its own merits and requirements for inspection and shall be selected as agreed upon in a contractual document.

1.3.1 Test Procedure A, Pulse Echo (non-contacting and contacting) is at a minimum a single transducer transmitting and receiving a longitudinal wave in the range of 0.5 to 20 MHz (see Fig. 1). This procedure requires access to only one side of the specimen. This procedure can be conducted by automated or manual means. Automated and manual test results may be imaged or recorded.

1.3.2 Test Procedure B, Through Transmission is a combination of two transducers. One transmits a longitudinal wave and the other receives the longitudinal wave in the range of 0.5 MHz to 20 MHz (see Fig. 2). This procedure requires access to both sides of the specimen. This procedure is automated and the examination results are recorded.

1.4 This practice does not specify accept-reject criteria.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C274 Terminology of Structural Sandwich Constructions

D3878 Terminology for Composite Materials

D5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation

E114 Practice for Ultrasonic Pulse-Echo Straight-Beam Contact Testing

E543 Specification for Agencies Performing Nondestructive Testing

E1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases

E1316 Terminology for Nondestructive Examinations

E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases

E1471 Guide for Identification of Fibers, Fillers, and Core Materials in Computerized Material Property Databases

SAE Standards

AIA Standard

ASNT Standards

Keywords

aerospace composites; fiber-reinforced polymer matrix composites; flat panel composites; honeycomb core; laminates; nondestructive evaluation (NDE); nondestructive inspection (NDI); nondestructive testing (NDT); polymeric matrix composites (PMC); sandwich core materials; ultrasonic testing (UT); ultrasound;

ICS Code

ICS Number Code 49.035 (Components for aerospace construction)

DOI: 10.1520/E2580-07

ASTM International is a member of CrossRef.