Metal-wood crane beam calculation

Objective. The development of structures and calculation of metal-wood crane beams are associated with specific difficulties. The article discusses the methods of calculation and design of metal-wood crane beams. In this case, an algorithm is described that allows designing systems that are rational in terms of material consumption. Methods. As an example, a metal-wood beam with a span of 12 m is used, which is supported by overhead cranes with a load capacity of 30 tf. The operation of a metal-wood crane beam was compared with a glue laminate crane beam without reinforcement. The reinforcement elements are "discarded" and replaced with elasto-yielding supports to calculate a glue laminate beam reinforced with metal elements (or a metal-wood beam). The flexibility of these supports is taken into account using the elastic support ratio r, which is determined depending on the stiffness of the supports, and the force in the metal elements is derived from the nodes balance. Result. In both variants of loading metal-wood crane beams, it was shown that the greatest bending moment occurred when the bridge wheel was located above the elastic support. Conclusion. It is rational to use a metal-wood crane beam when operating bridge cranes with a lifting capacity of up to 30 tf; metal-wood crane beams are recommended to be designed with spans up to 12 m; the comparison of glue laminate crane beams with metal-wood beams showed that metal-wood beams were 40-55% more efficient.

Pengaruh Posisi, Jumlah Layer Dan Mutu Kayu Terhadap Balok Laminasi Kayu Mahang Dan Kayu Meranti

Reduced forest products cause also reduced of large-dimensional wood that has high quality. One alternative to solve the problem is by doing laminate engineering by combining different quality wooden layers into specific sized beams as desired. The type of wood and the position of layer give effect to the laminate beam capacity. The aim of this research was to find out the flexural capacity (MOR) of Mahang and Meranti wood laminated beams which layers were varied which then the result of the laminated beam was compared with the solid beams. There were 3 types of laminate specimens made with dimension 5x7x76 cm3 which consisted of 7 layers; BL K1 beam consisted of 2 layers of Meranti wood at the top and bottom of the beam and 5 layers of Mahang in the middle; BL K2 beam consisted of 4 layers of Meranti wood at the top and bottom of the beam, and 3 layers of Mahang in the middle; and BL K3 beam consisted of 6 layers of Meranti wood at the top and bottom of the beam and 1 layer of Mahang in the middle. The test results showed that the use of wood of higher specific gravity at the outermost layer has increased the flexural capacity (MOR) and modulus of elasticity (MOE), particularly in laminated beams (Meranti wood and Mahang wood) with the same numbers of layers. Moreover, in same number or greater layer proportion between Mahang and Meranti wood, the result showed the increased of MOR and MOE of laminated beams compared with solid beam that has low specific gravity (Mahang).

PENGARUH PENAMBAHAN BAUT DAN PAKU TERHADAP KUAT LENTUR BALOK LAMINASI KAYU MAHANG DAN MERANTI

ABSTRACT The addition of bolts and nails as a shear connector on the laminate beam was expected to anticipate the problem on the laminate beam which only uses glue adhesive. The samples were a specimen of material properties and a specimen of the laminated beam, the dimension was 76 x 5 x 5 cm with three types of adhesive variation. The MOR value was obtained by one point load on the middle of the span. The value was the load and deflection, further calculated the value to get MOR and MOE. The MOR result of the addition of nail as the connector on the laminate beam by glue was increased 36.9%. In contrast, the addition of bolt was decreased 49.86% compared to MOR BL LM. The addition of nails and bolts to laminated beams that used glue already showed the effect to decrease the MOE value of the laminate beam.Keywords: Connector bolt and nail, Flexural strength, Laminate beam. ABSTRAK Penambahan baut dan paku sebagai perekat diharapkan dapat mengantisipasi masalah yang umum terjadi pada balok laminasi yang hanya menggunakan perekat lem. Sampel yang dibuat meliputi sampel properties material serta sampel balok laminasi berukuran 76 x 5 x 5 cm sebanyak 3 tipe variasi jenis perekat. Nilai MOR diperoleh dengan pemberian beban satu titik ditengah bentang. Nilai yang diambil adalah beban dan lendutan, yang kemudian dihitung untuk mendapatkan nilai MOR dan MOE. Hasilnya penambahan paku sebagai penghubung/perekat pada balok laminasi yang menggunakan lem, dapat meningkatkan nilai MOR sebesar 36,9%, sedangkan penambahan baut menyebabkan penurunan nilai MOR sebesar 49,86% dibandingkan terhadap nilai MOR BL LM. Penambahan paku dan baut pada balok laminasi yang menggunakan lem juga dapat menurunkan nilai MOE dari balok laminasi itu sendiri. Kata kunci: Perekat baut dan paku, Kuat lentur, Balok laminasi.

Modeling of tensile and bending properties of biaxial weft knitted composites

Within the scope of experiments, the effect of aramid and glass yarns as stitch and biaxial (warp and weft) yarns in the biaxial weft knitted (BWK) composite was compared. After production of four types of composite panel using the hand lay-up method, the tensile and bending properties of the BWK composites were investigated both experimentally and numerically. The composite with the glass stitch and biaxial yarns exhibited higher tensile and bending properties than did the composite with the aramid stitch and biaxial yarns. The good agreement between the experimental results and the numerical results validated the applicability of the finite-element method for the BWK composites. The laminate beam theory was utilized as another modeling method for calculation of the bending modulus.

Delamination Assessment in Structures Made of Composites Based on General Signal Correlation

This paper considers a vibration-based damage assessment approach which is based on the general idea for signal cross-correlation. Here the method is demonstrated and validated on a composite laminate beam and it is applied for the purposes of delamination assessment in composite structures. The method uses two measures of cross-correlation between two vibration signals measured in different points on the structure in order to diagnose the delamination. The linear cross-correlation as well as a new measure for nonlinear cross-correlation, the mutual information, are introduced and applied for the purposes of delamination assessment. The delamination assessment is based on the comparison of the measures for the healthy and the damaged state of the structure. In this study, the method is applied using the free decay responses of the beam. Two delamination indices are introduced and they are used for the purposes of delamination detection and localization.