Multi-span composite beam

Abstract

The development of wooden structures tends to create systems, types, elements and types of connection that would allow you to save wood while increasing the load-bearing capacity and best take into account its physical and mechanical features. One of the priority directions is the creation of lightweight composite bent structures based on wood. The scientific novelty of the article consists in the study of multi-span continuous composite beams, the use of which is possible both in new construction and reconstruction. Composite multi-span wood-glued beams with the proposed reinforcement scheme are an experimental design and to date, their work is poorly studied. The essence of the proposed design is to strengthen the lower zones in the spans of the beam and the upper zones of the beam at the location of the support with fiberglass on an epoxy oligomer. To perform the calculations, we set a model of a beam with three spans of 1.5 m. the Load is assumed to be evenly distributed along the entire length of the beam. A comparison of the structure to assess its rationality was carried out with an unreinforced glued beam with the same design scheme. The study found that, in contrast to wooden beams, the strength of composite beams with rational reinforcement of stretched zones increases by 24-27 %, and the deformability decreases by 8-13 %. From the point of view of the work, it is proposed to use the method of vacuum infusion, which is proven, which has a positive effect on technical and economic indicators.

Interpretation of Reflectograms of Seismic Acoustic Flaw Detection of Piles

“…Diagrams close to the reference ones cannot be obtained during real tests due to non-uniformities of the soil and the concrete. In this specific case, additional factors contributing to interferences are also neighbor secant piles and the soil reinforcement by cement grout jetting [13,14]. To confirm that the piles have no flaws, they are visually inspected along the entire depth during the pit excavation (Fig.…”

“…The obtained results confirm the influence of the soil uniformity on the signal purity. The less the structural uniformity of the soil, the more false characteristic peaks are obtained in the reflectogram [13,14]. Also, cement grout jetting for soil reinforcement is an additional signal distortion factor.…”

“…In addition to the absence of codes ruling the testing procedure, the seismoacoustic flaw detection has a very poor corps of research studies. The studies of the past years were aimed at the description of the physical process of propagation of oscillations in a solid body [8][9][10][11][12][13]. Typical reflectograms provided by manufacturers scarcely allow for high-quality and correct processing of the obtained results by the operator.…”

Rational structural solutions for triangular trusses

“…Деревянные стропильные системы являются эффективными несущими конструкциями. Одно из направлений развития деревянных конструкций -поиск конструктивных решений, повышающих их эксплуатационные качества [1][2][3][4]. Основной задачей при этом будет выявление взаимозависимости параметров конструкции и определение их гармоничного сочетания.…”