title: Analysis of bonded joints for small craft and marine applications

authors: Armeanu, Liviu Eduard

subjects: bonded joint

abstract: This Thesis investigates the possibility of replacing, in small craft and recreative boats, some of the more traditionally made joints (using tabbing) with ones made using structural adhesives (adhesive used where the load applied may cause the separation of the adherends [2]), which have the potential to be quicker to produce and have good fatigue resistance. It also focuses on methods that are available to a small and medium size boatbuilding or boat design company in order to design and produce a general safe, light weight adhesive joint. Several static tests were conducted in order to identify the characteristics of the materials to be joined and the properties of the adhesives investigated. A summary of the analytical theories available in order to determine the characteristics of the joints are presented and compared, and several finite element models have been investigated in order to determine the suitability of this method when using adhesive materials. This Thesis focuses first on Single-Lap joints, not only as a joint, but also as a way to compare the characteristics of the adhesives to be used. Three types of adhesives have been tested, two commercially available (Plexus MA550 and Sikaflex 252) and one commonly found on boatbuilding yards, a mixture of vinyl ester and Epiglass HT120 (a silica based filler). It was found that the Plexus MA550 adhesive performed well across different substrates (aluminium and composites) followed closely in performance by the vinyl ester/filler mixture. Very promising results were obtained when a carrier fabric was used inside the adhesive layer. Secondly, a very common type of joint, the T-joint, has been anti - symmetrically tested. A comparison has been made between a more traditionally produced joint (using a small fillet made from vinyl ester and microballoons based filler and EU-glass tabbing) with a joint produced using a fillet made from the above adhesives. It was found that the results from samples with the fillet using the vinyl ester/filler mixture are the closest to the benchmark samples and it seems to be the best candidate to replace the traditional joint, given the strength, failure mode, price and the availability. The joint using a Sikaflex 252 fillet has shown the most interesting results such that none of the materials forming the joint suffered any visible damage after deformation. The joint using a R20mm Plexus MA550 fillet has benefited from the stiffness and the good adhesion characteristics of the adhesive but in all the tests the panels joined ware damaged earlier than for the benchmark samples.

text: Analysis of bonded joints for small craft and marine applications This Thesis investigates the possibility of replacing, in small craft and recreative boats, some of the more traditionally made joints (using tabbing) with ones made using structural adhesives (adhesive used where the load applied may cause the separation of the adherends [2]), which have the potential to be quicker to produce and have good fatigue resistance. It also focuses on methods that are available to a small and medium size boatbuilding or boat design company in order to design and produce a general safe, light weight adhesive joint. Several static tests were conducted in order to identify the characteristics of the materials to be joined and the properties of the adhesives investigated. A summary of the analytical theories available in order to determine the characteristics of the joints are presented and compared, and several finite element models have been investigated in order to determine the suitability of this method when using adhesive materials. This Thesis focuses first on Single-Lap joints, not only as a joint, but also as a way to compare the characteristics of the adhesives to be used. Three types of adhesives have been tested, two commercially available (Plexus MA550 and Sikaflex 252) and one commonly found on boatbuilding yards, a mixture of vinyl ester and Epiglass HT120 (a silica based filler). It was found that the Plexus MA550 adhesive performed well across different substrates (aluminium and composites) followed closely in performance by the vinyl ester/filler mixture. Very promising results were obtained when a carrier fabric was used inside the adhesive layer. Secondly, a very common type of joint, the T-joint, has been anti - symmetrically tested. A comparison has been made between a more traditionally produced joint (using a small fillet made from vinyl ester and microballoons based filler and EU-glass tabbing) with a joint produced using a fillet made from the above adhesives. It was found that the results from samples with the fillet using the vinyl ester/filler mixture are the closest to the benchmark samples and it seems to be the best candidate to replace the traditional joint, given the strength, failure mode, price and the availability. The joint using a Sikaflex 252 fillet has shown the most interesting results such that none of the materials forming the joint suffered any visible damage after deformation. The joint using a R20mm Plexus MA550 fillet has benefited from the stiffness and the good adhesion characteristics of the adhesive but in all the tests the panels joined ware damaged earlier than for the benchmark samples.

year: 2010

title: El espacio como agente intersemiótico en la (de)construcción del significado poético (Space as an intersemiotic agent in the (de)construction of poetic meaning)

authors: Lopez-Fernandez, Laura

abstract: En este estudio se investigan nociones aportadas por la crítica literaria y socio-cultural en torno a la discursividad del espacio como modo de producción. Asimismo, se redefine el espacio poemático verbal en contraste con el espacio fractal y se propone un modo inclusivo de lectura del mismo basado en propuestas teóricas de diversas escuelas de pensamiento y nuevos espacios epistemológicos: formalismo (Víctor Shklovsky), postestructuralismo (Henri Lefebvre, Edward Soja Roland Barthes; Mitchell W. J. T.; Mieke Ball), psicología de la percepción (la Gestalt), el concepto de espacio negativo “Ma” (Alan Fletcher; Richard B. Pilgrim), la poética cognitiva (Gaston Bachelard; Peter Stockwell; Reuven Tsur). De modo particular, se analiza el concepto de espacio como agente semiótico en la poesía fractal de Ramon Dachs y Roger Olivella.

text: El espacio como agente intersemiótico en la (de)construcción del significado poético (Space as an intersemiotic agent in the (de)construction of poetic meaning) En este estudio se investigan nociones aportadas por la crítica literaria y socio-cultural en torno a la discursividad del espacio como modo de producción. Asimismo, se redefine el espacio poemático verbal en contraste con el espacio fractal y se propone un modo inclusivo de lectura del mismo basado en propuestas teóricas de diversas escuelas de pensamiento y nuevos espacios epistemológicos: formalismo (Víctor Shklovsky), postestructuralismo (Henri Lefebvre, Edward Soja Roland Barthes; Mitchell W. J. T.; Mieke Ball), psicología de la percepción (la Gestalt), el concepto de espacio negativo “Ma” (Alan Fletcher; Richard B. Pilgrim), la poética cognitiva (Gaston Bachelard; Peter Stockwell; Reuven Tsur). De modo particular, se analiza el concepto de espacio como agente semiótico en la poesía fractal de Ramon Dachs y Roger Olivella.

year: 2015

title: Ngati Rahiri versus Ngati Tamatera

authors: Hart, Philip

abstract: Conflict between Ngati Tamatera, of Ohinemuri, and Ngati Rahiri, of Te Aroha, was provoked by the latter believing that members of other hapu had received money for the Aroha Block to which they were not entitled. In addition, the two hapu disagreed over the block’s northern boundary. In early 1877 Ngati Rahiri threatened violence and even fired over the heads of several rangatira passing through their land, thereby challenging their right to intrude on it. In response, Ngati Tamatera, with the assistance of Ngati Koi, blocked the road to Te Aroha and also the Waihou River against Ngati Rahiri, although they permitted Pakeha to pass. Pakeha took a relaxed attitude to the conflict, not expecting any real battles occurring during a squabble they understood to have been caused by members of an inferior hapu having their names wrongly included in Crown grants.
After Ngati Tamatera erected two small and unimpressive pa to block both road and river, Ngati Rahiri retaliated by constructing a similarly unimpressive pa at Omahu, their settlement at Te Aroha. Apart from much posturing, the only actions taken were Ngati Tamatera sending back to Omahu an aged woman who had come down the river in a canoe and Ngati Rahiri stealing pigs and peaches and firing shots near a settlement. The Native Minister and various officials, notably James Mackay, intervened to resolve the conflict, which was ended with a reconciliation initiated by Ngati Tamatera and formalized by a large meeting of both hapu at Omahu.
Once this quarrel was settled, negotiations to enable the Crown to purchase the Aroha Block were resumed.

text: Ngati Rahiri versus Ngati Tamatera Conflict between Ngati Tamatera, of Ohinemuri, and Ngati Rahiri, of Te Aroha, was provoked by the latter believing that members of other hapu had received money for the Aroha Block to which they were not entitled. In addition, the two hapu disagreed over the block’s northern boundary. In early 1877 Ngati Rahiri threatened violence and even fired over the heads of several rangatira passing through their land, thereby challenging their right to intrude on it. In response, Ngati Tamatera, with the assistance of Ngati Koi, blocked the road to Te Aroha and also the Waihou River against Ngati Rahiri, although they permitted Pakeha to pass. Pakeha took a relaxed attitude to the conflict, not expecting any real battles occurring during a squabble they understood to have been caused by members of an inferior hapu having their names wrongly included in Crown grants.
After Ngati Tamatera erected two small and unimpressive pa to block both road and river, Ngati Rahiri retaliated by constructing a similarly unimpressive pa at Omahu, their settlement at Te Aroha. Apart from much posturing, the only actions taken were Ngati Tamatera sending back to Omahu an aged woman who had come down the river in a canoe and Ngati Rahiri stealing pigs and peaches and firing shots near a settlement. The Native Minister and various officials, notably James Mackay, intervened to resolve the conflict, which was ended with a reconciliation initiated by Ngati Tamatera and formalized by a large meeting of both hapu at Omahu.
Once this quarrel was settled, negotiations to enable the Crown to purchase the Aroha Block were resumed.

year: 2016