SU947349A1

SU947349A1 - Wooden beam

Info

Publication number: SU947349A1
Application number: SU813253067A
Authority: SU
Inventors: Леонид Михайлович Ковальчук; Георгий Ростиславович Баранов; Юрий Александрович Варфоломеев; Каститис Альфонсович Скирпстунас; Ирина Петровна Преображенская; Александра Семеновна Жукова; Раиса Никитична Верещагина
Priority date: 1981-02-24
Filing date: 1981-02-24
Publication date: 1982-07-30

Description

: Изобретение относитс к строительству и предназначено дл изготовлени несущих конструкций, преимущественно клееных дерев нных балок.: The invention relates to construction and is intended for the manufacture of load-bearing structures, mainly glued wooden beams.

Известна дерев нна балка, включающа составленные в пакет пластины из разных пород древесины, соединенные между собой на клею в плоскост х контакта, при этом пластины размещены в соответствии с распределением нормальных напр жений по высоте се- чени и характеристиками прочности древесины 1.A wooden beam is known, including plates made of different wood species, arranged in a package, interconnected by glue in the contact planes, while the plates are arranged in accordance with the distribution of normal stresses over the height of the section and the strength characteristics of wood 1.

Недостатком известной балки вл етс то, что в ней не решена проблема ослабл ющего действи стыкon сращивани пиломатериалов по длине и суч ков, так как стыки и пороки в пиломатериалах :значительно снижают их прочность по сравнению с прочностью-, чистой древесины определенной породы.A disadvantage of the known beam is that it does not solve the problem of the weakening effect of the joint splicing of sawn timber in length and knots, since joints and flaws in sawn timber: significantly reduce their strength compared to the strength of pure wood of a certain species.

Известна также дерев нна балка, включающа составленные в пакет пластины , соединенные между собой на клею, и металлические стержни, размещенные в каналах, выполненных в пластинахГ25Недостаток такол дерев нной балки состоит Б- том, что в зоне контакта древесина-металл возникает концентраци напр жений и трешйны при изменвНИИ температурно-влажностных условий эксплуатации. Применение арматуры усложн ет технологию изготовлени клееных конструкций (необходимо выполнение кансшов, заполнение каналов специальными кле ми, подготовка арматуPti} .A wooden beam is also known, including plates arranged in a package, interconnected with glue, and metal rods placed in channels made in plates G25 The disadvantage of a wooden beam tacol is B-that in the wood-metal contact zone there is a concentration of stresses and trashiny when changing temperature and humidity conditions. The use of reinforcement complicates the technology of manufacturing glued structures (it is necessary to perform cutting, filling channels with special adhesives, preparing reinforcement).

Арматура, размещенна в теле дерев нной пластины, не может реализовать Armature placed in the body of a wooden plate cannot realize

10 полностью своих прочностных свойств следовательно, металл расходуетс нерентабельно. Кркзме того, при воздействии огн несуща способность армированных конструкций снижаетс 10 completely of its strength properties, therefore, the metal is consumed unprofitable. In addition, when exposed to fire, the carrying capacity of reinforced structures decreases

15 значительно быстрее, чем массивных дерев нных.15 much faster than massive woods.

Наиболее близкой к предлагаемой вл етс дерев нна балка, включающа пластины, выполненные из разных Closest to the offer is a wooden beam, including plates made of different

20 пород,- соединенные между собой клеевыми прослойками, и усиливающий элемент, выполненный составным по высоте из отдельных соединенных между собой на клею пластин, размещен25 ных в раст нутой зоне, волокна которых ориентированы вдоль продольной оси балки ГЗЗ, В некоторых случа х при переменных температурно-влажностных услови х эксплуатации древесина 20 rocks, interconnected by adhesive layers, and a reinforcing element, made of composite height of individual interconnected on the glue plates, placed in the stretched zone, the fibers of which are oriented along the longitudinal axis of the GZZ beam, in some cases with variable temperature -humid conditions of exploitation wood

Claims

30 in the massive layer is deformed significantly more than in the reinforcing element, and because of this, large humidity stresses arise at the boundary. The purpose of the invention is to increase the carrying capacity by reducing the effect of wood flaws and eliminating moisture stress across the fibers. This goal is achieved in those in a wooden beam, which includes plates made of different species, interconnected by adhesive layers, and a reinforcing element made of composite height of individual interconnected on the glue plates, placed in the stretched zone, fibers which are oriented along the longitudinal axis of the beam, the reinforcing element is made in width of the plates joined by glue on the sides of the edges, and the plates are made of rocks of different strengths and stretched alternately in sh Akhmatny order in width and height of the element. FIG. 1 shows schematically a beam, a facade; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a section B-B in FIG. 1. The wood beam includes extreme plates 1 of a compressed zone of hard wood, plates 2 of the middle part of the beam cross section of low strength wood, a reinforcing element located in the most intense stretch of the stretched zone, made of plates of low strength rocks and 5 solid rock glued together by lateral edges, while the plates 5, for example larch, have a minimum number of natural defects and are placed along the edges and in the stretched zone of the section in accordance with the diagram of the strains with hundred audio beams in bending and strength characteristics of the materials. Due to the dispersion of the teeth of joints b and the natural flaws of wood (Fig. 2), the carrying capacity of the beams is increased by 10-15% as compared with adhesive beams, in which the toothed joints in the stretched zone occupy the entire width of the layer. In addition, the use of composite widths reduces the annual length of annual rings, thereby reducing the stresses caused by the uneven drying of the wood in tangential and radial directions with varying temperature and humidity conditions of operation. In this case, the likelihood of TpeitjHH occurring in the structure is reduced. The manufacture of beams of this design can be made without a significant change in technology, designed for mass production of structures of conventional sections. This provides annual savings of RUR. with wood saving of 1, 2 thousand m with the release of 15 thousand m -production. Claims of the invention A wooden beam, including a flat-. Tins made of different rocks, interconnected in tight layers, and a reinforcing element made of composite height of individual interconnected on the glue plates, 1 in the stretched zone, the fibers of which are oriented along the longitudinal axis of the beam, characterized by that, in order to increase the carrying capacity due to the weakening of the influence of wood flaws and the elimination of moisture stress across the fibers, the element is made composite along the width of the plates interconnected on the glue side edges, The plates are made of rocks of different strengths and are placed alternately in a checkerboard order in width and height of the element. Sources of information taken into account in the examination 1. I. I. Grin. Investigation of the carrying capacity of laminated beams composed of three layers of different wood foam. Construction and architecture, Novosibirsk, MVUZ, I960, No. 3, p. 42 ,.

2. Kovalchuk LM. Pasting of wood materials with plastics and metals. M., Lesna industry, 1963, p. 240

3. USSR author's certificate for application 2894970 / 29-33, cl. E 04 C 3/12, .1980 (prototype).

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