Location

Brunswick, ME

Start Date

1-1-1992 12:00 AM

Description

The detection of disbonds in riveted lap joints is of increasing interest to the aerospace community. Adhesively bonded and riveted lap joints are used to bond the thin overlapped sheets of aluminum which comprise the outer skin of an aircraft. Through time, the integrity of the bond can become compromised by disbanding, leading to corrosion and stress concentrations at the rivets and subsequent cracking leading to joint failure. A thermal technique for determining bond integrity in these structures has been investigated by Winfree, et al [1]. This technique involves active heating of the aircraft fuselage with a measurement of the temperature on the outer surface of the structure with an infrared imager. By even application of heat to the outer surface of the lap joint, details of the inner structure become thermographically detectable. A disbond will prevent heat from penetrating from the surface layer to the subsurface layers, resulting in an increase in surface temperature over the disbond. Thermographic detection of disbonds excels over other methods by being a noncontacting, quantitative method for inspecting large areas in a short period of time.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

11A

Chapter

Chapter 1: Fundamentals of Standard Techniques

Section

Thermal Techniques

Pages

457-464

DOI

10.1007/978-1-4615-3344-3_58

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Numerical Solutions for Heat Flow in Adhesive Lap Joints

Brunswick, ME

The detection of disbonds in riveted lap joints is of increasing interest to the aerospace community. Adhesively bonded and riveted lap joints are used to bond the thin overlapped sheets of aluminum which comprise the outer skin of an aircraft. Through time, the integrity of the bond can become compromised by disbanding, leading to corrosion and stress concentrations at the rivets and subsequent cracking leading to joint failure. A thermal technique for determining bond integrity in these structures has been investigated by Winfree, et al [1]. This technique involves active heating of the aircraft fuselage with a measurement of the temperature on the outer surface of the structure with an infrared imager. By even application of heat to the outer surface of the lap joint, details of the inner structure become thermographically detectable. A disbond will prevent heat from penetrating from the surface layer to the subsurface layers, resulting in an increase in surface temperature over the disbond. Thermographic detection of disbonds excels over other methods by being a noncontacting, quantitative method for inspecting large areas in a short period of time.