scholarly journals Metal-wood crane beam calculation

Author(s):  
A. K. Yusupov ◽  
H. M. Muselemov ◽  
T. O. Ustarhanov

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.

2019 ◽  
Vol 12 (1) ◽  
pp. 44-55
Author(s):  
Ayad A. Ramadhan

This paper presented the effect of bending on multi-layer of hollow columns of Hybrid materials (Carbon-Glass /epoxy-Alumina) composite this effect occurred and volume fraction of fibers. An experimental procedure was developed to study the performance of these effects under bending load using a hydraulic bending device type (MATEST. SRL) testing machine. This study has three forms through the selection of columns hollows width to thickness (a/b) (0.5, 1 and 2) with three types of layers of samples (2,4 and8) layers. The ultimate load of failure for each Hybrid/epoxy-Al2O3 had been determined and specified the optimum volume fraction (Vf) due to the effect of mixing 50% and 60% were low in the case for compared 55% volume fraction. To simulate this problem the researcher used Explicit Mesh for AUTODYN under ANSYS-15 software, it was found that maximum bending load for Hybrid/ Epoxy-Al2O3 Specimens, the maximum load of specimens increased with increasing number of layers from 2L to 8L. The results also identified that the maximum load capacity by 55% volume fraction and a/b=0.5 of all composite specimens was highest from the others types of (50% and 60%) volume fractions and (a/b=1 and a/b=2) .Also, the Increasing ratio of stress capacity for specimens have 4 to 2 layers (4/2)  and 8 to 4  (8/4) for experimental results have maximum value with increasing by 48.19%  and 46.84% at (Sp.4#8/Sp.2#4) and (Sp.8#6/Sp.4#6) respectively.


2019 ◽  
Vol 106 ◽  
pp. 38-48
Author(s):  
Maciej Sydor ◽  
PIOTR POHL

Load-bearing capacity and characteristic forms of destruction of furniture joints made with rastex 15 and P-10 clamex fasteners. The study tested the relationship between the load and angular deflection in furniture joints. The tests were carried out for two types of fasteners and five types of materials: chipboard, MDF, hardwood plywood, glued pine boards and glued oak boards. The furniture joint samples contained two fasteners preloaded only with a bending moment (without application of shear forces). The results were converted per single fastener specifying: its maximal load capacity, 50 mrad (2.9°) limit deflection and rigidity coefficient. It was found that rigidity is a better structural property of the tested joint types than their load capacity. As far as rigidity is concerned, the most durable is the combination of oak glued board – rastex 15 fastener (13.2 Nm bending moment per fastener), while the least durable combination is chipboard – clamex P-10 fastener (4.8 Nm bending moment per fastener). Photographic documentation of damaged furniture joint samples was prepared and analysed. In case of chipboard and MDF combinations (where the load is determined by the combined material), the combined boards suffer a disastrous damage, while in combinations of plywood boards and pine or oak glued boards, (where the capacity is determined by the fastener), both clamex P10 and rastex 15 fasteners are damaged.


2021 ◽  
Vol 2 (55) ◽  
pp. 18-24
Author(s):  
E.S. Lustenkova ◽  

The article presents a method for calculating and designing spherical roller gears with a double-row pinion. The studied gears are analogs of planetary gears with a double-wheel pinion. They make it possible to implement a wide range of gear ratios. The advantages of spherical roller gears include small dimensions, low material consumption, and layout properties. A special feature of the proposed calculation algorithm is the search for optimal geometric gears parameters according to the criteria of maximum efficiency coefficient taking into account maximum load capacity for a given maximum radial dimensions. The main criterion of strength is fatigue endurance. The method includes design and verification calculations. It makes it possible to develop the small-sized speed reducers for low-speed drives for various purposes.


2020 ◽  
Vol 14 (1) ◽  
pp. 66-75
Author(s):  
Behnam Mehdipour ◽  
Hamid Hashemolhosseini ◽  
Bahram Nadi ◽  
Masoud Mirmohamadsadeghi

The purpose of this research is to investigate the performance and efficiency of reinforced slope in the stability of geocell layers in unsaturated soil conditions. Slope reinforced with geocell acts like a beam in the soil due to the geocell having a height (three-dimensional). Due to its flexural properties, it has moment of inertia as well as bending strength, which reduces the displacement and increases the safety factor of the slope. Taking into consideration unsaturated conditions of soil contributes a lot to making results close to reality. One of the well-known models among elastoplastic models for modeling unsaturated soils is Barcelona Basic Model, which has been added to the FLAC2D software by codification. Changes in thickness, length and number of geocell layers are remarkably effective on slope stability. The results show that the geocell's reinforcing efficiency depends on the number of layers and depth of its placement. As the depth of the geocell's first layer increases, the lateral and vertical side elevation of the upper part of the slope increases with respect to the elevation. Load capacity increases with increasing geocell length. By increasing the length of the geocell layer, the joint strength, the mobilized tensile strength, and the bending moment are increased. At u/H = 0.2, an increase in the bending momentum of about 20% occurs with increasing geocell thickness. In u/H = 1, the increase in bending momentum is 10.4%. In addition, by increasing the thickness of the geocell, the Value of moment of the inertia increases and, as a result, the amount of geocell reinforcement bending moment increases.


2019 ◽  
Vol 25 ◽  
pp. 100824 ◽  
Author(s):  
Zhongwei Zhao ◽  
Bing Liang ◽  
Haiqing Liu ◽  
Lina Xian

2020 ◽  
Vol 10 (3) ◽  
pp. 1016 ◽  
Author(s):  
Anna Szymczak-Graczyk

The paper presents the effect of considering the substrate under the floor—insulation in the form of closed-cell polyurethane spray foam, which is used for insulating surfaces particularly exposed to mechanical impact. The layer of thermal insulation was made by spraying, which prevents the occurrence of thermal bridges due to tight filling of the insulated space. It seems extremely important to adopt the appropriate material characteristics of an insulating layer. The basic thermophysical properties of polyurethane foam justifying its choice as an insulation material were the values of its thermal conductivity coefficient (0.022 W/(mK)) and density (36 kg/m3). However, what was the most important for the calculations provided in the work was to determine the stiffness of the foam subgrade so as to assess its impact on the floor load capacity. The paper includes calculations for a floor slab characterized by a static diagram, with all edges free (unfixed), loaded in strips circumferentially. The reinforced concrete slab was 6 × 6 m long, 0.25 m thick, and made of C20/25 concrete resting on an elastic substrate. Calculations were made for two variants taking into consideration two values of subgrade stiffness. The first variant concerned the subgrade stiffness for sprayed polyurethane foam insulation. On the basis of laboratory tests in situ made according to the standard procedure, its average value was assumed as K = 32,000 kN/m3. The second, comparative, computational variant included the subgrade stiffness equal to K = 50,000 kN/m3. A variation approach to the finite difference method was used for static calculations, adopting the condition for the minimum energy of elastic deformation while undergoing bending that was accumulated in the slab resting on a Winkler elastic substrate. Static calculations resulted in obtaining the values of deflections at each point of the discretization grid adopted for the slab. The obtained results have proved the necessity of calculating the floor as a layer element. For the reference substrate with the subgrade stiffness K = 50,000 kN/m3 that was adopted in the work, the value of the bending moment was 17% lower than when taking into account that there was thermal insulation under the floor slab, causing an increase in the deflection of the slab and an increase in its bending moment. If a design does not include the actual subgrade stiffness of the layer under the floor slab, it results in an understatement of the values of the bending moments on the basis of which the slab reinforcement is designed. Adherence of insufficient concrete slab reinforcement may cause subsequent damage to floor slabs.


2019 ◽  
Vol 24 (2) ◽  
pp. 96
Author(s):  
Rahma Nindya Ayu Hapsari ◽  
Ilham Nurhuda ◽  
Nuroji Nuroji

Composite structures of concrete slabs and steel beams require shear connectors to transfer shear force between steel beams and concrete slabs. The strength of stud shear connector specified on SNI 03-1729-2013 only considers the effect of stud diameter, however the length of a stud may influence its behavior and strength. This research observes the effects of length and diameter (𝓁/𝒹) of shear connectors on the strength. This research was conducted using the push out method explain in AS-4347- Part I. The test specimens observed in this research were concrete and steel composites, composing IWF 350x175x11x14 mm and concrete blocks of size 450x225x160 mm. The studs were made of steel reinforcements with diameter (𝒹) of 10, 16 and 22 mm, were welded on IWF with 5 mm weld thickness. The length of studs for each stud diameter were 4d, 5d, and 6d. The results indicate that the increase in stud diameter will increase the load capacity of stud. The length of studs effect its load capacity. A slim stud experiences large bending moment at the base of the shear connector. The results show that the highest value of load capacity is measured at specimens with 𝓁/𝒹 ratio of 5.


2011 ◽  
Vol 94-96 ◽  
pp. 830-833 ◽  
Author(s):  
Dong Mei Zhao ◽  
Ying Xu Zhao ◽  
Yan Xia Ye

In this paper, the effect of the non-uniformity settlement of ground foundation on the upper frame structure is studied. It takes a four-story space frame structure with two spans as an example. The different pedestals are installed at the joint of column footing, which respectively form the fixed supported model and the elastic supported model. Basin shaped settlement is applied in each model. The result shows that the beams are principally suffered with the bending moment and the columns principally suffered with axial force, shear force and bending moment, and that the elastic support model has certain economy.


2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Denis Molnár ◽  
Miroslav Blatnický ◽  
Ján Dižo

A bridge crane is a type of crane that is designed for lifting / lowering and transferring material in the horizontal direction and is used mainly in production halls, warehouses and transship points. A part of the lifting mechanism of the bridge crane is a crane hook on which the load is suspended. Sufficient strength is required from the crane hook in order to be able to withstand high loads relatively well. The most stressed part of the crane hook is the curved inner surface. This surface is considered critical in terms of strength. The goal of this paper is to select a suitable crane hook for a single girder bridge crane with a load capacity of 500 kg and a strength analysis of the selected crane hook. Strength analysis is performed by two methods, first is based on analytical calculation and second is based on finite element method (FEM) performed in Ansys software. The comparison of the obtained total stresses from both methods is the part of the analysis. From the results of the FEM analysis and analytical calculation it can be stated that the selected crane hook RSN 05 P - DIN 15401 with a load capacity of 500 kg is suitable for the above-mentioned bridge crane. It can also be concluded that the total stress determined by the analytical calculation is lower by 9.8 % compared to the stress obtained from the Ansys software.


Author(s):  
G S Sundaresan ◽  
Sandeep Kumar Jain B ◽  
Srikanth A ◽  
M Abdul Shakeel

A brief introduction about floating docks, its advantages and types have been described. The naval architectural considerations which play a significant role in the design of floating dock have been explained. Typical ratios of L/B and L/D as a function of Dock’s lifting capacity have been presented. Empirical formulation for the same have also been indicated wherever applicable. Intact stability and its criterion as applicable for a floating dock have been described. Critical positions during evolution of docking operation and important considerations while performing stability calculations have been highlighted. Attention has also been drawn to the damage stability of floating dock. Aspects of longitudinal and transverse bending moment, which are the governing aspects in the scantling calculations have been described. Also typical methods for securing and mooring of floating dock, without compromising on flexibility for docking operations have been described. Methodology and consideration which has to be kept in mind while using design software (such as NAPA) have been indicated. Simple size optimization techniques which result in steel / ballast volume reduction have also been explained.


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