Bending moment resistance of dowel corner joints in case-type furniture under diagonal compression load
We investigated bending moment resistance under diagonal compression load of corner doweled joints with plywood members. Joint members were made of 11-ply hardwood plywood of 19 mm thickness. Dowels were fabricated of Beech and Hornbeam species. Their diameters (6, 8 and 10 mm) and depths of penetration (9, 13 and 17 mm) in joint members were chosen variables in our experiment. By increasing the connector’s diameter from 6 to 8 mm, the bending moment resistance under diagonal compressive load was increased, while it decreased when the diameter was increased from 8 to 10 mm. The bending moment resistance under diagonal compressive load was increased by increasing the dowel’s depth of penetration. Joints made with dowels of Beech had higher resistance than dowels of Hornbeam. Highest resisting moment (45.18 N·m) was recorded for joints assembled with 8 mm Beech dowels penetrating 17 mm into joint members Lowest resisting moment (13.35 N·m) was recorded for joints assembled with 6 mm Hornbeam dowels and penetrating 9 mm into joint members.
Withdrawal Strength of Dowels in Plywood and Oriented Strand Board
Plywood and oriented strand board (OSB) are being used increasingly in the construction of upholstered furniture frames. Yet there is little information available concerning the holding strength of various fasteners, and, in particular, dowels in these materials. A study was conducted accordingly, to obtain basic information about the holding strength of dowels in both plywood and oriented strand board. Results of the tests were incorporated into predictive expressions that allow designers to estimate withdrawal strength as a function of the diameter of the dowels, their depth of embedment and the density of the composite material. Given the variability of the composite materials, significant differences between predicted and observed values must be expected. The maximum differences observed in the tests amounted to no more than 44 percent, however, so that the expressions developed nonetheless provide reasonable first estimates of dowel withdrawal strength. Coefficients of determinations for the expressions varied from 0.868 to 0.623. The results indicated that the generous use of adhesives tends to compensate for inherent material problems such as delamination. Ozet: OSB (Oriented Strand Board) ve kontrplak›n doflemeli mobilya iskeletlerinin konstruksiyonunda kullan›m› gun gectikce artmaktad›r. Ancak, bu tur kompozit malzemelerin deiflik balant› elemanlar› ve ozellikle kavela ile tutma mukavemeti hakk›nda yeterli veri yoktur. Bu cal›flmada kavelan›n kontrplak ve OSB ile tutma mukavemeti hakk›nda gerekli temel veriler salanmaya cal›fl›lm›flt›r. Test sonuclar› say›sal formuller haline getirilerek urun tasar›mc›lar›n›n kavela tutma mukavemetini kavela cap›, derinlii ve kompozitin younluunun fonksiyonu olarak tahmin etmeleri amaclanm›flt›r. Kompozit malzemedeki degiskenlik gozonune al›nd›¤›nda, test sonuclar› ile istatistiksel tahminlerden elde edilen sonuclar aras›nda buyuk bir fark olmasi beklenir. Buna karfl›n, test deeri ile istatistiksel tahmin aras›ndaki en buyuk fark›n % 44 olmas›, elde edilen formullerin kavela mukavemetini makul bir duzeyde tahmin ettiini gostermektedir. Formullerin determinasyon katsay›lar› .868 ile .623 aras›nda seyretmifltir. Ayr›ca, test sonuclar› fazla miktarda tutkal kullan›m›n›n delaminasyon gibi kompozite iliflkin baz› problemlerin ortadan kald›r›lmas›na yard›mc› olduunu
A survey of aquaculture production economics and management
Abstract The literature on production economics and management of fish culture has grown as aquaculture has matured as a commercial industry. Salmon, catfish, shrimp and trout are the focus of this literature survey as a reflection of the volume of research that has been completed on these species and their importance in US production and world trade. In addition, a discussion of low resource production systems is included that is dominated by tilapia and carp culture systems. A brief overview of the principles of aquaculture production economics and management is presented followed by a review of economic studies.