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Polymeric materials are susceptible to minor damage, which is undetectable. Without timely and effective repair treatment, the damage may deteriorate the integrity of the materials and ultimately result in material failure and catastrophe. Autonomous warning and simultaneous damage repair are of great practical significance yet difficult to realize. Herein, we introduce a smart coating with autonomous warning and repairing of damage by the simple incorporation of nanosensors embedded with phenanthroline as a corrosion indicator and inhibitor. The electrochemical corrosion resulting from coating damage can be rapidly indicated by a prominent orange-red color in just five minutes. In addition to the warning function, the smart coating exhibits efficient self-repairing in the defective region, as reflected from the disappearance of the electrochemical admittance peak. This simple and powerful strategy dependent on a single active component to achieve an autonomous warning and repairing effect is highly expected to provide a new avenue for enhancing the security and longevity of other polymeric materials.

This investigation assesses the change of aerodynamic characteristics of triangular and star-shaped damaged airfoils with repair patches. Both experimental and numerical methods to determine aerodynamic coefficients are used in this study. The test model is a NACA 641-412 airfoil full span, which is considered by using five schematics: Clean model, damaged model, upper repaired model, lower repaired model, and fully repaired model. Repair patches are chosen based on the Aircraft battle damage repair (ABDR) manuals. Various effects of repair schemes on triangular and star-shaped damages are quantitatively and qualitatively illustrated. A novel visualization method by paint and oil is used in wind tunnel tests to study the effects of repair patches on the damaged airfoil.

Summary. The increasing use of composite structures in aircraft constructions has made it necessary to develop repair methods that will restore the component’s original design strength without compromising its structural integrity. In this paper, the complex repair technology of the composite wing of a light plane, which was damaged during an aircraft crash, is described. The applied repair scheme should meet all the original design requirements for the plane structure.

Recent military operations have highlighted the need for new expedient pavement repair capabilities to improve current guidance on airfield damage repair. Damaged or distressed military airfield pavements must be repaired with expedient methods and durable materials to minimize the time the pavement is removed from service and to reduce or eliminate additional closure times for subsequent repairs. Extensive research was conducted to develop several airfield pavement repair techniques that could be applied across the full spectrum of military airfield repair operations. This paper focuses on the research conducted to develop a new foam backfill technology for airfield pavement repairs. Results of initial laboratory and field tests showed that rigid, poured polyurethane foam is the most applicable backfill solution for deployed locations because of its ability to expand to several times its shipped liquid volume when mixed, reducing the logistical burden of transporting aggregate backfill materials. This paper describes laboratory and field experiments that used foam backfill and prototype equipment to develop a pavement repair technique that supports threshold and objective aircraft pass levels defined for expedient airfield repairs. The research included laboratory testing, full-scale field testing, and simulated and actual aircraft traffic tests with C-17 and F-15 aircraft. Results of these tests validated and certified the foam backfill repair technique for military aircraft use. However, these experiments also identified material and equipment limitations that will require additional research before the repair technique is adopted by military repair teams. Conclusions and recommendations for future equipment and material improvements are provided.

In the future, the Royal Netherlands Navy (RNLN) will face growing challenges at sea in an environment of ever increasing complexity, variety and speed. Ship systems will continue to evolve and become more interconnected. The ship’s crew will be expected to do more with fewer numbers in less available time. To be able to meet these challenges the RNLN have started the Manning and Automation roadmap to realize effective and integral support for operations on board. A critical requirement for these steps to be made is the integration of information to enable automation to integrally support the crew in their operations. On current ships, information and automation of separate systems often are not integrated and survival relies on the crew connecting the dots of an ever-increasing complexity of data. Furthermore, during incidents crews rely on paper-based systems for Battle Damage Repair management to create an overview and support the ship’s operations. These paper-based systems are slow, fault-sensitive, manpower-intensive and will potentially result in missed opportunities or critical errors, especially in a time-critical State 1 environment. The RNLN have started several projects on the Manning and Automation roadmap to develop integration and automation of the Internal and External battle into an Integrated Mission Management System. This paper will describe the current process and foreseen improvement for Battle Damage Repair management to support a more effective Internal and External Battle on ships of the RNLN with optimised crew numbers. It will demonstrate a large step in effectiveness and crew optimisation can be made by employing existing and emerging technology.

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Structure and Infrastructure Engineering on 2016, available online at: http://www.tandfonline.com/10.1080/15732479.2014.993660 This paper investigates the seismic behaviour of closely spaced fixed-base and isolated building structures in near-fault (NF) zones. Seismic pounding of fixed-base structures is considered at different heights, being from one or both opposite sides and at different seismic gap width. The response evaluation results of fixed-base buildings drive towards providing limited, but adequate, seismic gaps to perform seismic isolation. This aims at reducing structural responses with no seismic pounding under limited gaps, minimising the possible damage repair and diminishing the needed maintenance works due to strong NF earthquakes. To achieve that untraditionally, the paper presents a recently proposed seismic isolation system, named roll-in-cage (RNC) isolator, as a non-traditional solution to avoid direct seismic pounding of isolated buildings with their surrounding adjacent structures. It was found that the RNC isolator’s buffer mechanism is able to draw down any possible pounding of the isolated superstructure to be within the isolator solid limits. This entirely prevents direct structure-to-structure pounding but on the account of amplifying its acceleration and drift responses. However, such amplified responses might lead to only minor or moderate structural damage under sever NF earthquakes with 1.20g peak ground acceleration. Nevertheless, such damage could be avoided entirely using stiffer RNC isolators to achieve reduction of seismic response up to 69.0% under the same severe loading conditions and limited seismic gaps with no seismic pounding. Consequently, the RNC isolator could be an efficient solution for aseismic design in NF zones considering limited seismic gaps.

Research was conducted at the U.S. Army Engineer Research and Development Center to evaluate leaner, lighter equipment for deployable debris removal post missile strikes for airfield damage repair (ADR). LiDAR scans were obtained prior to and after the initial debris removal and were also used in the final debris removal process when using vacuums and sweepers. Photogrammetry was used to obtain measurements and to calculate volumes. A market survey of available loading and sweeping equipment was conducted to populate a database of physical dimensions and time relationships according to identified ADR tasks. Selected equipment was evaluated for maneuverability and efficiency in a realistic environment. Results indicate that mini track loaders with a maximum rated weight of 3,000 lb are capable of performing all identified ADR tasks with an efficiency at or better than the currently utilized 10,000-lb track loaders. Results also indicate that sweeper vacuums with a maximum rated weight of 3,500 lb are capable of performing all identified ADR tasks with an efficiency at or better than the currently utilized 20,000-lb vacuum trucks.

Effective implementation of BDAR(Battlefield Damage Assessment and Repair) can compensate equipment for battlefield losses, maintain combat effectiveness at the meantime. Under the conditions of modern information warfare, a variety of advanced reconnaissance, detection methods and widely used precision strike weapons, are making the battlefield highly transparent, however,the living environment of weaponry will become very seriously, more brutal battlefield injuries of weaponry will come up simultaneously. Equipment battlefield damage repair is facing new challenges,therefore,the BDAR military equipment which can maintain and enhance the combat capability has great practical significance under conditions of informationalization.

Laboratory technicians are typically portrayed as manual workers following routine procedures to produce scientific data. However, technicians in vertebrate paleontology laboratories often describe their work in terms of creativity and artistry. Fossil specimens undergo extensive preparation – including rock removal, damage repair, and reconstruction of missing parts – to become accessible to researchers. Technicians called ‘fossil preparators’ choose, apply, and sometimes invent these preparation methods. They have no formal training, no standard protocols, and few publications to consult on techniques. Despite the resulting diversity of people and practices, preparators and their work are usually absent from research publications, making them ‘invisible technicians’ in Steven Shapin’s sense. But preparators reject the view of their work as predictable or simple; in particular, many preparators value art training, the aesthetics of prepared fossils, and the process of creative problem-solving in their work. Based on interviews and participant observation and drawing from literature in science studies, sociology of work, and anthropology of craft, I ask why these technicians compare themselves with artists and how this portrayal affects scientific practice and social order in laboratories. I argue that associating artistry and creativity with their work distances preparators from ideas of unskilled technical work and technicians’ low status, thus improving their social role in the laboratory community and preserving their power over laboratory practices.

By means of computation and analysis of damage tolerance of composite laminates with hole or crack, the conclusion is brought forth that crack on laminates can’t be cut into hole to improve the residual strength; otherwise the damage will become more serious. The method and conclusion can be reference and basis for battle damage repair of airplane composite component.

Against the sticking patch design problems of pass damage of aircraft skin repair, by using the calculation method of mechanical analysis, the stress analysis of pass damage is completed. The calculation methods are used quantitatively to determine the sticking patch dimension of pass damage repair, which is compared with analysis sticking patch design method calculated by the repair empirical equation of aircraft skin of Airline Company. The reason of error is analyzed and the measure to correct empirical equation method is put forward. The optimization of the critical parameters of pass damage empirical equation is completed.

Recent military operations have highlighted the need for modernisation of airfield damage repair capabilities for concrete pavements to eliminate long closure periods. Damaged or distressed military airfield pavements must be repaired using expedient methods and durable materials to minimise the time the pavement is removed from service, and to reduce or eliminate additional closure times for subsequent repairs. As a result of this need, extensive research was conducted to develop multiple concrete pavement repair techniques that could be applied across the full spectrum of military airfield repair operations. Developed methods included placing rapid-setting cementitious materials, foreign object debris covers and precast concrete panels over various backfill materials. Newly developed backfill techniques included poured and injected polyurethane foams and dry-placed, rapid-setting flowable fill. The combination of these materials resulted in several new repair techniques that could return a damaged pavement to aircraft traffic within 4–6 h of initiation of the repair. This paper summarises the development of these repair technologies, and describes their performances under accelerated pavement testing and aircraft validation tests. The paper also includes recommendations as to the suitability of each technique for specific operational scenarios, based on field evaluations.

A new damage-adaptive bone remodeling model, in which an algorithm incorporating both strain and damage stimuli, is developed in this paper. Typically, a human proximal femur model is established to predict the bone mass distribution during bone remodeling process. And human physiology damage-repair cycle is considered in the model. The governing equations of the mathematical model, digesting the predecessors’ ideas, are numerically solved and implemented into ANSYS software via the user interface of finite element algorithm. With the aid of this novel model, the whole healing behavior of human proximal femur is elucidated properly.

Modeling of laser-induced optics damage has been introduced to benchmark existing optic usage at the National Ignition Facility (NIF) which includes the number of optics exchanged for damage repair. NIF has pioneered an optics recycle strategy to allow it to run the laser at capacity since fully commissioned in 2009 while keeping the cost of optics usage manageable. We will show how the damage model is being used to evaluate strategies to streamline our optics loop efficiency, as we strive to increase the laser shot rate without increasing operating costs.

We tried to repair the surface of damaged poly-methyl methacrylate and glass using a simple coating and evaluated the transmittance of direct component of light. We coated a repairing material on the damaged surface of the sample. After the first sandblasting, the transmittance and the calculated conversion efficiency of CPV decreased due to the damage derived by the sandblasting. However, after the first coating, they made a recovery due to the effect of the repairing coating. In the second step (sandblasting and coating), the recovery was also observed. Instead of replacement of damaged lens or module, the coating can bring the performance back into the improved condition.

The ability to repair battle damage is an important capability for helicopter structures, as they are vulnerable to ballistic impact damage from small arms fire and therefore more likely than fixed wing aircraft to suffer damage in a combat environment. This paper outlines computational investigations to aid the development of a battle damage repair capability for a helicopter composite main rotor blade. The effectiveness of the proposed repair concept was assessed using a finite element analysis that involved a relative comparison of three models, namely the pristine, damaged and repaired models.

This paper summarises recent research conducted at the Defence Science and Technology Organisation in the area of aircraft battle damage repair, covering aspects such as ballistic testing, ballistic damage prediction, non-destructive damage inspection, structure residual-strength assessment, repair materials and techniques, repair design approaches, repair implementation and demonstration. The research has been focused on military helicopter composite structures. This paper provides an overview of a wide range of research conducted and detailed information in selected areas. Considerations for future research directions are also briefly discussed.

The function of the Airport is like a terminal which in this case serves passenger aircraft as a stop, departure, or just an airplane stopover. at the airport there are various kinds of series of activities related to aircraft, such as transporting / dropping passengers and goods, conducting refueling, aircraft maintenance, aircraft damage repair, and so forth. The apron is part of the airport which is the area used in accommodating the aircraft to load and disassemble or degrade passengers and freight, park, and refuel. Pavement is the main structure in apron construction. This means that the apron is required to be able to accept and bear the aircraft load and traffic on it is planned properly. This study aims to calculate the rigid apron pavement construction designed so as to obtain pavement with carrying capacity capable of serving air traffic in accordance with the aircraft traffic plan.Keywords: Airport, Apron, Rigid Pavement

An explosion of electric furnace caused a local damage of the roof in steel industrial building. This building has a saw-tooth roof covering, constructed from prestressed plates with 12.62 m of span. The explosion caused a local damage of plates prestressed ribs, which are the roof main structural elements. The technical condition of the plates has been assessed as an emergency state due to the loss of the plates’ strength and the hazard of their fall down. The damage repair has been presented herein.

The Defence Science and Technology Organisation (DSTO), Australia, Delegation Generale Pour L’Armement (DGA), France and Eurocopter have carried out collaborative research in the area of battle damage repair techniques for military helicopter structures. Australian and French participants have focused on depot and field repairs, respectively. This paper summarises the research conducted at DSTO to develop battle damage repair methods for a helicopter composite frame-skin junction (FSJ) subjected to damage caused by a typical threat weapon. A generic BDR design approach was successfully applied, which involved use of a reverse engineering approach to determine the load requirements, application of a rapid repair design approach, and validation of the design using finite element analyses and experimental testing.

This paper presents an answer to the statement ‘Please recommend the damage repair to the building that is required to restore the building to its pre-hurricane or earthquake condition.’ Copyright © 2007 John Wiley & Sons, Ltd.

For the purpose of facing battle damage that a fighter is subject to in combat, following recovery procedures such as damage assessment, repair design and structural integrity evaluation are investigated. A sample study is presented on the battle damage of F-15 ECS bay, which is comprised of damage assessment and repair design based on ABDR(Aircraft Battle Damage Repair) skills and work procedure complying with AFTO(Air Force Technical Order) forms. Further, the flight safety of repaired structure is validated and the time the permanent repair should be done is estimated through the evaluation of structural integrity such as the calculation of static strength and fatigue life.

Nature provides a wide range of materials with different functions and which may serve as a source of bio-inspiration for the materials scientist. The article takes the point of view that a successful translation of these ideas into the technical world requires more than the observation of nature. A thorough analysis of structure-function relations in natural tissues must precede the engineering of new bio-inspired materials. There are, indeed, many opportunities for lessons from the biological world: on growth and functional adaptation, about hierarchical structuring, on damage repair and self-healing. Biomimetic materials research is becoming a rapidly growing and enormously promising field. Serendipitous discovery from the observation of nature will be gradually replaced by a systematic approach involving the study of natural tissues in materials laboratories, the application of engineering principles to the further development of bio-inspired ideas and the generation of specific databases.

Combat aircraft that are damaged and reside on the ground are completely ineffectual to air component commanders. Aircraft battle damage repair (ABDR) aims to rapidly restore these damaged aircraft to some level of combat capability. To be effective, the repairs must allow the aircraft to return to combat in time to affect the outcome of the battle. The Composite Group at Department of Materials, Queen Mary College, University of London, has worked on various aspects of the rapid repair concept for composite materials. In the present paper in particular, the vacuum infusion method is highlighted as an alternative reliable bonded infield repair approach for composite monolithic skins. The study identifies certain technical challenges that the repair technique must address to be viable. Results are presented from a novel toughening method developed by incorporating polyester and carbon veils at the infused bondline, while single scarf coupons as well as full scale testing data demonstrate the effec...

The United States Army Engineer Research and Development Center was tasked by the US Air Force Civil Engineer Center to improve the saw cutting and excavation production rates of crater repairs in thick portland cement concrete (PCC) pavements for airfield damage repair (ADR) scenarios. The concrete cutting and excavation rates, along with the required manpower, using Caterpillar SW45 and Sw60 wheel saws and Caterpillar and Volvo excavators, respectively, in 18-in.-thick PCC pavement did not meet the required production rates during the 2009 Operational Utility Assessment (OUA) in Avon Park, Florida. The current ADR techniques, tactics, and procedures (TTPs) indicate cutting of pavement around a crater should be completed in 22 min or less, and excavation (breaking and removal) of the repair area should be completed in 23 min or less for an 8.5- by 8.5-ft crater. Various equipment (e.g., wheel saws, excavators, rock splitter, anchors, etc.) and methods were evaluated for sawing and removing concrete and base course material in 18- and 24-in.-thick PCC and 5-in.-thick hot-mix asphalt. This report presents the technical evaluation of various sawing and excavation equipment and methods for improving the efficiency of removing damaged pavement associated with crater repair.

In this paper, the possible repair technology problems about ship borne aircraft were analyzed. According to the present research progress, the surface damage repair, lever measurement, general repair technology, and preventive maintenance were reviewed and studied.

The RAF has been undertaking peacetime repairs on composite rotor blades, fibreglass radomes and panels on a variety of combat aircraft types for many years. However, the Service's main experience in the repair of aircraft structures manufactured from carbon fibre composite (CFC) material has been related to the Harrier II. In any future conflict involving air power, battle damaged aircraft, including the Harrier II, will have to be repaired rapidly to meet operational requirements. The repair techniques used may have to differ from those undertaken in peacetime but they must still aim to restore the full static strength of the aircraft within the time constraints imposed by the operational situation. Therefore, aircraft battle damage repair (ABDR) is a carefully planned alternative to conventional repair techniques. This paper describes the main CFC structures of the Harrier II and outlines the variety of RAF peace and wartime structural repair procedures applied to the aircraft. Examples are provided of various simple and complex repairs. Greater emphasis on adhesively bonded repairs is called for if Harrier II experience is to aid in the logistic support of Eurofighter 2000 (EF2000) in peace and war.

The concept of aircraft expedient repair (AER), more commonly known as aircraft battle damage repair (ABDR), dates back to World War I, when the United States Air Service used parts from French farm machinery to keep aircraft flying. Despite a continuous evolution in strategy through a subsequent World War, a Cold War, multiple conflicts, and modern irregular warfare, the overall mission of AER remains constant. Implementation of AER operations continues to ensure commanders and war-fighters have the assets needed to execute their missions. Nonetheless, AER methods are challenged by modern aircraft designs, advanced structural materials, and increasingly lethal threats. Given the evolving demands of combat and technology, AER concepts of operations are constantly required to adjust. This paper will describe how AER has adapted to evolving strategies and tactics, advanced technologies, and operational constraints to guarantee mission success. Real-life experiences will be provided to relate changes in technologies and strategies with the AER concept of operations.

The ability to rapidly repair damaged airfield sections is of paramount importance. It is imperative to restore flight operations in the shortest possible time. Currently, there are several methods that pertain to expedient airfield damage repair. One method uses cast-in-place, high-early-strength concrete. The cast-in-place procedure entails completely removing the damaged portion of airfield pavement and subsequently placing fresh concrete into the resulting void. A second method involves the use of precast concrete panels. The precast concrete panel procedure requires removing a damaged section of runway and replacing the damaged section with one or more precast panels. Obviously, the removed damaged section and the precast section must be congruent. This report details the precast concrete panel repair method, including its advantages and disadvantages. Additionally, this report summarizes information on repairs using single precast panels and repairs using several connected precast panels. There are several different methods that utilize single panel and connected panel repair. The most common of these are the Fort Miller Super-Slab(registered trademark) Method, the Michigan method and the URETEK Method. Each of these options is discussed in detail.

This paper describes Navy plans for ship battle damage repair (SBDR). The goal is to repair battle damage as far forward as possible. This would return lightly damaged ships to service quickly, reduce time lost for transit and save heavily damaged ships for subsequent repair. Damaged ships would proceed to the rear until they find a facility with adequate capability and capacity. Tenders and repair ships in forward areas will play an important role. In the Persian Gulf, both USS Stark (FFG-31) and USS Samuel B. Roberts (FFG-58) were damaged, but survived. In each case, they returned to the United States for restoration, but only after repairs in theater made them seaworthy. In 1988 the assistant chief of naval operations for surface warfare fashioned a contingency plan. It relied heavily on ongoing efforts to define a new repair ship, AR(X). Under the resulting plan, shore intermediate maintenance activities (SIMA) and mobile technical units (MOTU) will augment tenders and repair ships. In forward areas, tenders will colled damaged ships in a triage for repair or cannibalization. Restoring seaworthiness and mobility will be the first priority, then repairing combat systems. Heavily damaged ships will be patched and sent to the rear for further repairs.

The authors present the case of a big three phase generator step-up transformer with three windings and five leg core, from its failure and diagnosis of damage up to repair on site and tests to prove the quality of work, including first preventive tests after its return in operation.

In support of the U.S. Air Force Air Combat Command, the U.S. Army Engineer Research and Development Center (ERDC) was tasked to develop and test innovative techniques, materials, and equipment for expedient and sustainment repairs of small bomb craters in airfield pavements. This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation procedures, and repair performance. After 3 hr of cure, each crater was trafficked under controlled traffic conditions to determine the ability of the repairs to support the gross load of an F-15E aircraft. Results of the traffic tests identified multiple repair materials that can be used for expedient and sustainment repairs of concrete airfield pavements. Both the laboratory and full-scale traffic tests were conducted at the ERDC in Vicksburg, MS, from February to November 2006. Experimental results were used to develop ADR criteria for rapidly repairing small craters.

Increased concern with the requirement to maintain high combat sortie rates during short duration, high intensity conflicts has created the need for more accurate methods of predicting the downtime of combat damaged aircraft. This paper reports on the results of a program conducted for the Air Force to develop procedures for estimating combat damage repair times of inflight and parked aircraft.

Base on the intelligent pigging survey result, it is believed that the external corrosion was caused by disbondment of the asphalt enamel coating on the 36″ Badak-Bontang pipeline. An electromagnetic technology method is selected to locate and measure the coating damage level. In conjunction with the coating damage evaluation, coating repair was also being assessed. Following field demonstrations from various vendors, a liquid epoxy coating was finally selected, due to its performance, ease of application and relatively long pot life. Following the receipt of the final coating survey report, the defective areas along the pipeline were positively identified, and excavated for verification. The pipe which have coating damage were repair by removing the existing coating, cleaned back to bare steel to allow application of the new liquid epoxy coating. This was an excellent example where research, field-testing and evaluation through good engineering practices have resulted in significant cost savings.

This paper briefly discusses some of the external forces that act upon a typical distribution system. These forces can cause damage, either immediately or over long periods of time, which in turn affect the systems reliability and integrity. This paper examines methods in repairing conductor damage and protection measures that can be implemented to establish a higher level of system reliability. Because higher stresses occur at the support locations where the cable is constrained, this paper concentrates on damage repair in these areas.

The armored family of vehicles (AFV) is a US Army program to design and field the next generation of armored tracked vehicles as a single system. Encompassing twenty-six different vehicle configurations, the AFV places special emphasis on commonality in the design. It is currently in the concept definition phase. Work which examines the impact that component commonality has on battle damage repair is reported. >

The improvised repair of battle damage to military equipment on the battlefield is a vital part of a repair strategy and one that can win battles. Such battle damage repair (BDR), although improvised, should be carefully planned for, and technicians must be schooled and trained in the special techniques required. While much can be done on the battlefield, BDR can be considerably enhanced during the design phase, where an awareness of the problem can do much to influence equipment design. One such approach to BDR is described, along with a training philosophy. Background experience drawn from operations in World War II and the Falklands campaign, and typical examples of repairs and their influence on design are given. >

This bibliography is published by the Joint Technical Coordinating Group on Aircraft Survivability (JTCG/AS) Central Office. The Joint Aeronautical Commanders Group (JACG) chartered the JTCG/AS. The JTCG/AS organization is depicted on page 3. The purpose of this document is to provide a listing of technical reports, which have been published under the auspices of the JTCG/AS. This bibliography contains abstracts which are organized by date of publication for publications produced by the three principal subgroups; Susceptibility Reduction, Vulnerability Reduction, and Survivability Methodology. Administrative support publications, aircraft battle damage repair publications and publications pertaining to aircraft survivability but not funded by the JTCG/AS are also included. An index for each of these areas is provided following the collection of abstracts.

United States Air Force (USAF) Aircraft Battle Damage Repair (ABDR) strategies, techniques and technologies are directly applicable to NASA efforts to develop on-orbit repair capabilities for the International Space Station (ISS). At the operational level, USAF repair strategies developed since the Vietnam War stressed the need for methodical damage assessment, categorization, and repair. This approach should be adopted for future repair operations onboard the ISS. At the technical level, repairs based upon material ultimate properties, preparation for damage to multiple systems and specialized damage effects have shaped ABDR techniques to provide flexible repair strategies for Air Force aircraft. These techniques should also be considered when developing ISS repair strategies. Overall, a baseline for comparison between ISS repair and ABDR clearly demonstrates the need for further technical interchange. Lessons learned from ABDR experiences with provide early insight into techniques and strategies proposed for on-orbit ISS repair operations.

An evaluation of nine rapid runway repair (RRR) techniques was performed using the systems analysis approach. This analysis was based on a logical step-by-step procedure of examining the smallest details of each RRR system. The primary objective was to evaluate the RRR systems against criteria (evaluation factors) that were identified to be important in RRR. These criteria included repair time, cost, complexity, etc. The final results showed that the best RRR systems are asphalt blocks, fiberglass-reinforced plastic (FRP) mats, and FRP foldable mats. These repair techniques possess the desirable advantages in a RRR system. They are fast, simple, and cost effective, and extensive training is not required. This study was conducted methodically and each phase was carefully thought out. It reflects the opinions of the author and leading RRR experts. This analysis is not intended to make the decision of which RRR system to implement; it is merely a tool to clearly state the procedures, factors, and rationale that are used to make a decision. Keywords: Airfield Damage Repair (ADR), FRP, Infrared heater, Base survivability.

Reliability of complex facilities, such as nuclear power plants, under construction or in operation is fundamental to the safety of humans and the natural environment. The key reliability-related factors are absence of errors in structural design and calculations, proper selection of materials and the manufacturing technology, quality of the materials used and the onsite welding operations, conditions of operation and in-service inspection. Despite the fact that much attention is given in the course of the NPP design and operation to ensuring reliability, the experience of operation has demonstrated that there is a potential for crack formation in welded joint No. 111 of the PGV-1000 M steam generator. The crack nucleation and growth mechanism has not been yet unambiguously identified. This paper presents the results of a study into the causes for the metal damage in the region of welded joint No. 111 between the hot header and the steam generator vessel's nozzle of Dn1200.

AN opportunity to become acquainted with the engineering expertise available at RAF Stations and to study the degree of involvement in design and manufacture occurred recently when visiting Abingdon and Marham. An aircraft maintenance and storage depot, RAF Abingdon's prime activity centres around the Engineering Wing which undertakes major servicing on Jaguar and Hawk aircraft and more recently, Buccaneer as well, together with various long‐term modification programmes. Responsibility is taken for assessing complex aircraft repairs, the recovery, salvage and transportation of all RAF, Royal Navy and Army fixed wing aircraft and in addition, assisting when necessary, the Aeronautical Inspection Branch in the recovery of crashed civilian aircraft. Some specialist tasks are also carried out, such as aircraft weighing and support for the RAF's Inspectorate of Recruiting, as well as housing the Aircraft Battle Damage Repair School. Storage of Jaguar aircraft is also undertaken as well as some VC 10 work.

AM-2 and British Class 60 trackway are compared as surfacing materials for bomb damage repair of runways. Each mat was evaluated on the basis of its operational characteristics, performance under load, and dynamic effects on aircraft. A field test was conducted to gather data on the performance of each mat under load, and a computer code, TAXI, was used to calculate aircraft response to the mats. AM-2 showed marginally superior load capacity and aircraft response; however the operational characteristics of the Class 60 trackway are far superior to those of AM-2. Class 60 trackway was concluded to be a superior surfacing materials for bomb damage repair.

An analysis of 15,000 repair estimates written nationwide on 1973 model passenger cars has been completed by State Farm Mutual Auto Insurance Company. Among the findings presented in this paper are the distribution of impact points around the car, distribution of repair cost, repair and replacement frequencies of certain components, and an analysis of repair cost spending by component assembly. A procedure is described which will monitor the crash damage sustained by new cars through the systematic collection and analysis of insurance company damage repair estimates. The availability and limitations of other insurance industry data sources are also discussed.

Two concrete-cutting technologies utilizing high-pressure waterjets have been investigated to assess their feasibility in achieving rapid cutting rates (30 sq ft/min) to facilitate bomb damage repair to runways. The current cutting rate of abrasive waterjets was established as 0.25 sq ft/min for a 60 hp system. Present scaling information indicates that for the near term the technology cannot feasibly achieve the desired cutting rate without a major technical breakthrough. Data from laboratory tests of linear cutting with a single carbide pick assisted with a waterjet indicate that high cutting rates are feasible with that technology. The waterjet-assisted mechanical cutting technology, however, has not been developed as a concrete cutting system. Prototype concepts are proposed in this report and an estimate is made of the power requirement to achieve the desired cutting rate (250 hp to cut 30 sq ft/min).

The purpose of this interim document is to provide documentation of airfield damage recovery (ADR) techniques within the 18th Engineer Brigade in Europe. This information can be used by the researcher and troop user alike to provide the repair of craters necessary to restore an airfield's horizontal construction to operational capability. The long-range purpose is to develop improved systems allowing a field commander to respond to various levels of hostility with a minimum of manpower, time, and cost. Current information within the state of the art of ADR can be used by units in the field for planning, estimating needed materials, organizing, and then accomplishing war damage repair missions to airfield pavements. The methods, materials, and techniques presented are those currently available for war-damaged airfield runways, taxiways, aprons, and roadways.

A nonlinear, finite-element computer code was developed for use in predicting the performance of repaired bomb craters. The code is capable of calculating the stresses, strains, and deflections produced by single- and multiple-wheel aircraft gear configurations. The apparent crater profile can be input as a series of linear approximations that is used by the code to modify material properties to reflect pushback and fallback crater debris from in situ native materials. (Author)