Outline report a visit to Kenyalang National ParkIntroduction Our English Society chose Kenyalang National Park as its excursion destination for 2008BodyContent 1 Group of thirty Society members and five teachers left the school in a chartered bus One teacher brought along a laptop loaded with information about the park All anticipating an enjoyable weekendContent 2 Arrival two hours later All wanted to try camping The teachers were such a great help and the team spirit shown by all was refreshing After eating, go to headquartersContent 3 Chose a short trail Able to name a plant or insect by looking up information on the internet Tired to complain about the lumpy ground
Content 4 After breakfast, packed up and returned to the park headquarters Told that best time to see any animal park was early in the morning or late in the eveningConclusion Reported at the Society’s meeting that Kenyalang National Park was a suitable destination for overnight school trips
Outline report on a SAA One Day Symposium on Structural Validation & HealthMonitoring of Adhesive JointsIntroduction Society for Adhesion & Adhesives One Day Symposium on Structural Validation and Health Monitoring of Adhesive Joints, held at the Society of the Chemical Industry, 15, Belgrave Square, London, 19th April 2007BodyContents 1 This meeting was well attended and useful discussions took place. The topic is of increasing interest as bonded metal joints and composite structures are forming an ever larger proportion of modern aircraft structures Monitoring methods are useful during flight testing and are being developed to monitor structures in service to reduce the amount of inspection required.Contents 2 Discussed the use of this method on adhesively bonded wing structures - stringer to skin bonding - on the BAE Jetstream Series and 146 aircraft These were bonded with 3Ms AF®-163 a tough and well-known film adhesive The objective was to compare predicted deformations with those measured by digital imaging.Contents 3 Jeff has found that quantitative measurements of adhesive/adhered strains and displacements and in-situ imaging under load provide a useful way of understanding the micromechanical behavior of an adhesively bonded joint Results were compared with finite element predictions. It was concluded that the optical image correlation method provided a consistent, quick and relatively simple method for making measurements
Contents 4 The full paper should be read for more detail but this is an interesting method that could prove very useful. This paper compared experimentally measured strains generated from neutron diffraction and moiré interferometry experiments with those predicted from finite element analysisContents 5 The third paper, entitled ‘Measuring Fatigue Damage in Bonded Joints Using the Back-Face Strain Technique’ was given by Alejandro Graner-Solana from the University of Surrey. This method uses single lap joints with strain gauges attached to the back face a short distance from the joint ends Changes in back-face strain are measured as the damage evolves; the location of the gauges is criticalContents 6 At 50% of shear strength, failure began after about 12,000 cycles One of the main aims of this project was to use the experimental back-face strain data to validate fatigue damage models for the adhesive The reason for this is that, although the one-phase model fitted the experimental data, at a given load, very well, if the same damage parameters were used, it was limited when applied at different loads; see the full paper.
Contents 7 Paper four, entitled ‘Modified Acoustic Emission for Structural Damage Monitoring of Complex Structures’ was given by Dr Christophe Paget of Airbus UK. This paper described Acoustic Emission (AE) equipment called Vigilant developed by Ultra Electronics and Airbus. Its purpose is to locate structural damage in complex structures such as aircraft It would be useful to have continuous monitoring in critical areas to save regular inspections and to find defects at an earlier stageContents 8 The fifth paper was given by Steve Ogin from the University of Surrey with the title, ‘Disbond Monitoring in Bonded Composite Joints Using Embedded Chirped- Fibre Bragg Grating Sensors’. Once again disbond and disbond growth were of interest This paper presents recent work on a novel optical technique using chirped fibre Bragg gratings [CFBGs],which can both detect disbond initiation and monitor disbond growth to within about 2mmContents 9 It can be concluded form this work that disbond initiation and disbond propagation can be monitored using CFBG sensors embedded in composite adherends If the CFBG sensor extends the full length of the overlap of a single lap joint, disbond development at either end of the overlap length can be measured
Contents 10 The sixth paper, entitled ‘Dielectric Analysis of Ageing Structural Adhesives’ was given by Professor Dick Pethrick of The University of Strathclyde. Dielectric analysis can be used to monitor the cure process and ensure that an adhesive has been cured properly Prof. Pethrick shows that both water ingress into an adhesive and the changes this produces at the interface in aluminium alloys, by effects on the oxide layer, can be monitoredContents 11 The seventh paper, entitled ‘Planes, Trains and Automobiles: Ultrasound Technologies for the Characterisation of Adhesives and the Inspection of Adhesively Bonded Engineering Structures’, was given by Dr Richard Fremantle of Wavelength NDT Limited. As the title suggests, this paper discussed problems from a wide range of industries Topics discussed were skin to stringer bonds in aircraft wings, masts for large yachts and inspection of adhesive bonds in carsContents 12 The eighth and final paper was given by Simon Pickering from the University of Bath and was entitled ‘Inspection of Adhesive Bonding Using Pulsed Thermography’. This technique of pulsed transient thermography involves using a short duration, high intensity flash of light to heat up the surface of a sample The heat then diffuses into the body of the sample
Conclusion This was another very interesting day in which a significant amount of new information was presented.