Search results

IRIS is a new ultrasonic system for inspecting air‐cooled heat exchangers. It employs the conventional pulse echo technique for measuring the wall thickness, but uses a novel method for displaying the measurements. All of the measurements made during a complete scan, around the circumference of the tube, are displayed on an oscilloscope screen to produce a stationary, rectilinear picture of the circumferential cross section. Missed and false measurements are easily recognised and can be compensated for by extrapolation of the valid measurements. The novel display allows wall thicknesses to be measured, virtually down to zero in ideal circumstances.

Steinheil Optronik GmbH of West Germany, a wholly‐owned subsidiary of British Aerospace plc, has developed a cost‐effective solution to testing the full performance characteristics of a gyroscopic device.

Rolls‐Royce has received certification for the RB211‐535 to be used for test flights on Russia's Tupolev Tu‐204 airliner.

The deck‐landing qualification test series on Aerospatiale's Dauphin SA 365N (naval version) helicopter have just been successfully completed off the coast of Brest.

The corrosion of Ti and Ti‐Hf25% alloy at 28°C (room temperature) in 20% MC1 and 20% H2SO4 solutions in the presence of 1g/litre of cations such as Fe+3, Cu+2, Ni+2 in each case and of several organic inhibitors has been studied. Cationic additions of Fe+3 and Cu+2 to 20% H2SO4 inhibit much better than similar additions to 20% HC1 solution and generally exhibit higher inhibitor efficiencies than the organic inhibitors studied. The addtions of Fe+3 and Cu+2 to corroding media shift the electrode potentials to noble values. However Ni+2 additions are not found to be effective.

United Technologies' Pratt & Whitney has received an order for jet aircraft engines valued at $75 million from Scandinavian Airlines System (SAS) of Stockholm.

Sheen Instruments report that although their range of gloss meters — particularly the pocket gloss meter — have again headed their sales during the past twelve months, with their equally extensive range of viscometers second, most new developments have been in coating thickness guages.

Impact and fatigue are critical loading conditions for composite aerostructures. Compression behavior after impact and fatigue is a weak point for composite fuselage panels. The purpose of this paper is to characterize experimentally the compression behavior of carbon fiber reinforced plastic (CFRP) stiffened fuselage panels after impact and fatigue.

In total, three panels were manufactured and tested. The first panel was tested quasi-statically to measure the reference compression behavior. The second panel was subjected to impact so as to create barely visible impact damage (BVID) at different locations, then to fatigue and finally to quasi-static compression. Finally, the third panel was subjected to impact so as to create visible impact damage (VID) at different locations and then to quasi-static compression. The panels were tested using ultrasound inspection just after manufacturing to check material quality and between different tests to detect impact and fatigue damage accumulation. During tests the mechanical behavior of the panel was monitored using an optical displacement measurement system.

Experimental results show that the presence of impact damage significantly degrades the compression behavior of the panels. Moreover, the combined effect of BVID and fatigue was proven more severe than VID.

The paper gives information about the compression after impact and fatigue behavior of CFRP fuselage stiffened panels, which represent the most realistic loading scenario of composite aerostructures, and describes an integrated experimental procedure for obtaining such information.