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| Registros recuperados: 51 | |
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| Davies, Peter; Choqueuse, Dominique; Bourbouze, G.. |
| Although X-radiography has been widely used in studies of damage in composite materials, micro-tomography has received less attention, due to the high cost and limited availability of equipment. However, micro-tomographic analysis is a powerful tool, allowing 3D images of sections through sandwich materials to be obtained without specimen preparation. Four examples from a recent study are presented here, which show how micro-tomography can provide unique information on the quality of honeycomb sandwich structures, information on damage mechanisms and internal details of through thickness reinforcement in pinned foam cores. |
| Tipo: Text |
Palavras-chave: Inspection; Adhesive; Meniscus; Pins; Damage. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14061/11311.pdf |
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| Davies, Peter. |
| This paper describes the influence of seawater ageing on composites used in a range of marine structures, from boats to tidal turbines. Accounting for environmental degradation is an essential element in the multi-scale modelling of composite materials but it requires reliable test data input. The traditional approach to account for ageing effects, based on testing samples after immersion for different periods, is evolving towards coupled studies involving strong interactions between water diffusion and mechanical loading. These can provide a more realistic estimation of long-term behaviour but still require some form of acceleration if useful data, for 20 year lifetimes or more, are to be obtained in a reasonable time. In order to validate extrapolations... |
| Tipo: Text |
Palavras-chave: Seawater; Immersion; Durability; Damage; Coupling. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00340/45167/44603.pdf |
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| Jeannetaud, P; Krawczak, P; Bequignat, R; Pabiot, J; Bord, C; Vancon, M; Bard, M; Lemascon, A. |
| Fractography deals with the microscopic study of the fracture surfaces of a structure in order to define the initiation and the propagation of the damage and then the failure history of the structure (stress, environment ...). Today, we are able to identify the causes of the failure of metallic parts based on pictures of typical fracture surfaces, but there is nothing similar for composite materials. However, the increasing amount of literature devoted to fractography, as well as the constitution of "brain storming" groups on a European level confirm scientific interest in this fracture analysis mode that permits a better understanding of the existing relationship between the material's microscopic structure and its macroscopic mechanical behaviour. In... |
| Tipo: Text |
Palavras-chave: Fractures; Damage; Failures; Ship technology; Composite materials; Endommagement; Rupture; Défaillance; Analyse d'avaries; Fractographie. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1060.pdf |
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| Sèbe, Maxime; Kontovas, Christos A.; Pendleton, Linwood. |
| Collisions between ships and whales raise environmental, safety, and economic concerns. The management of whale-ship collisions, however, lacks a holistic approach, unlike the management of other types of wildlife-vehicle collisions, which have been more standardized for several years now. In particular, safety and economic factors are routinely omitted in the assessment of proposed mitigation solutions to ship strikes, possibly leading to under-compliance and a lack of acceptance from the stakeholders. In this study, we estimate the probability of ship damage due to a whale-ship collision. While the probability of damage is low, the costs could be important, suggesting that property damages are significant enough to be taken into consideration when... |
| Tipo: Text |
Palavras-chave: Whale-ship collision; Damage; Cost; FSA; Wildlife-vehicle collision; Risk assessment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71327/69757.pdf |
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| Maurin, Romain; Baley, Christophe; Cartie, Denis D. R.; Davies, Peter. |
| This paper describes results from tests to examine the influence of through-thickness pinning on in-plane shear behaviour, measured by tensile loading of +/- 45A degrees specimens. Samples were produced by both aeronautical and marine manufacturing processes. As few previous studies have investigated pinning of marine composites these were also subjected to out-of-plane shear delamination tests. For both carbon/epoxy laminates the pins reduce the apparent in-plane shear modulus and strength. Pins modify the strain field measured by full-field image analysis, and slow damage development. A new damage mechanism, transverse pin cracking, was observed. |
| Tipo: Text |
Palavras-chave: Z-pinning; Shear; Mode II; Damage; Acoustic emission. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00113/22390/20186.pdf |
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| Barnouin, Bruno; Renaud, P. |
| The main conclusions drawn from examinations made by an expert over the last twelve years on boats in the Bay of Arcachon, including both motor and sailing boats, are presented. The different types of damage most frequently observed in different areas of the boats are described, with distinctions made between superstructures, areas below the water-line and other components. The damage is defined, common repair methods are described and simple design modifications to avoid the problems are discussed. In conclusion, it is apparent that the problems related specifically to aging of the material are rare or very rare. With improved fabrication methods and mastery of the design process in-service experience fully justifies the position of composite materials as... |
| Tipo: Text |
Palavras-chave: Motor boats; Inspection; Accidents; Yachts; Damage; Ship technology; Composite materials; Plaisance; Réparation; Accident; Dommage; Avarie. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1066.pdf |
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| Tarfaoui, Mostapha; Gning, P.b.; Davies, Peter; Collombet, F. |
| The impact behavior of composite materials has been extensively studied but interest has been centered on flat plates. For underwater applications, thick composite cylinders are employed and several questions must be addressed concerning the influence of accidental impact. The aim of this work is to study the dynamic response of tubular structures. Such structures find many applications but the damage upon impact is not taken into account during their dimensioning. However, at the time of their handling or in service the damage introduced by accidental impact can compromise their capacity to fulfill their function. The cylinders are thick and consist of epoxy matrix and glass fiber reinforcement. After having observed the nature of the damage related to... |
| Tipo: Text |
Palavras-chave: Size effect; Scale effect; Damage; Impact; Filament winding. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2458.pdf |
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| 松田, 清明; 宮本, 啓二; 佐藤, 禎稔; MATSUDA, Kiyoaki; MlYAMOTO, Keiji; SATOW, Tadatoshi. |
| 近年，連続的にナガイモ掘取りを行う機種が開発 され，利用され始めている.今回，従来から使用さ れているバックホー方式(K機)と掘取り方式の異なる3機種(A，SおよびT機)の掘取り機について， 作業性能を明らかにするとともに，各掘取り機の負 担面積や利用経費について検討した. 1)収穫作業に携わる作業者数は6-12人と供試機 により異なるが，概して能率の高い機種ほど作業 者は多い. 2 )各供試機の作業能率は， K機が2.2a/hであるのに 対して， A機が5.8a/h， S機は3.8a/h， T機が3.7a/h といずれも高能率である.10a当り投下労働量は， それぞれ27.8-32.4，20.8，21.0，21.9人・時である. 3 )各供試機の作業精度は，無傷の本数割合がいず れも98%以上と高く，損傷や掘残しの割合は極め て低い. 4 )各供試機の負担面積は， A機が4ha，K機は1.5ha， S機とT機が2.5haであり，その時のha当り機械利 用経費は，それぞれ556千円， 1,113 -1,173千円， 687千円， 699干円となる.各供試機の導入が不利 となる下限面積は， K機を他作業に利用するとい ずれも0.49-0.56haの範囲である. 従って， A機は高能率であるが多くの労働力や 前後処理に他の作業機を必要とし，大規模農家向 きである.また， K機は作業能率が低いが，少人 数でも作業が可能なことから小規模農家に適し，S機やT機は中規模農家に適している. Diggers of the backhoe type, the trencher type, and the plow type have been mainly used to harvest Chinese yams until... |
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Palavras-chave: ナガイモ; 掘取り機; 作業能率; 作業精度; 損傷; 負担面積; 経費; Chinese yam; Digger; Working capacity; Operating accuracy; Damage; Coverage cost. |
| Ano: 2001 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2831 |
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| Penteado, Susete do Rocio Chiarello; Carpanezzi, Aparecido Antonio; Neves, Edinelson José Maciel; Santos, Álvaro Figueredo dos; Flechtmann, Carlos Alberto Hector. |
| Este é o primeiro registro do ataque de besouros (Curculionidae, Scolitinae), no Brasil, causando danos em plantios de nim, entre 7 e 10 anos, em Brejinho de Nazaré, Tocantins, constado em junho de 2009. Os insetos foram identificados como, Xylosandrus compactus (Eichhoff), Cryptocarenus diadematus Eggers, 1937 e Hypothenemus sp. Westwood, 1836. Os plantios atacados apresentavam crescimento abaixo do esperado para a região, baixa produção de sementes, desfolhamento acentuado e rebrota intensa nos ramos, seguida por morte de brotos jovens e/ou do ápice do ramo. A ação dos insetos provocou pontos de exsudação intensa de goma nos orifícios provocados. O fato tem similaridade com a síndrome denominada “declínio do nim”, relatada na África.doi:... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Damage; Stress; Scolytinae; Ambrosia beetles; Azadirachta Danos; Estresse; Scolytinae; Besouros da ambrosia; Azadirachta.. |
| Ano: 2011 |
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/179 |
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| Paiva,Paulo Eduardo Branco; Parra,José Roberto Postali. |
| This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait) Milhocina® and borax (sodium borate) in the field, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: True fruit flies; Protein bait; Damage; IPM; Citros. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452013000200015 |
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| Registros recuperados: 51 | |
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