Development of a simulation dump truck dynamics model to estimate loads acting on its carrier and load platform when loading and dumping bulk loads

It is important for mining dump trucks to minimize the weight of the carrier and the load platform while maintaining a sufficient level of their rigidness and strength. This requirement significantly affects the weight of the transported material, the cost of transportation and, consequently, the economic efficiency of mining operations. Processes of loading and dumping of bulk loads, which is transported by dump trucks, make a significant contribution to reducing the service life of the carrier. Therefore, proper consideration of the bulk load dynamics is an important and relevant task. Contemporary systems for calculating the dynamics of solids allow for joint modeling with applications designed to calculate the dispersed body dynamics. This approach helps to obtain adequate loads in the pivots and force links of the model, to analyze the loading of the load platform, to asses the durability of the dump truck elements, to define the geometry of the load platform. In order to perform the simulation, it is required to develop a mathematical model of a dump truck, including all its key elements and subsystems, a model of the bulk load, and a model of the load platform. The purpose of the study is to develop a mathematical model of a mine dump truck to determine the loads in the pivots and force links connected to the carrier and the load platform for the strength calculations and durability analysis. The calculations are made with the combined use of the solids dynamics calculation system and the application to calculate the dynamics of dispersed bodies.

Comprehensive Evaluation of BIM Calculation Quantity in Domestic Construction Engineering Based on Fuzzy Comprehensive Evaluation

Nowadays, with the leap-forward development of computer technology and the transformation of information technology management concepts, China’s construction industry is quietly entering the era of refined management. Accurate estimation and cost control have become among the key considerations of the construction industry. For the calculation of engineering quantity, there are already many software devices that can be used for the calculation of engineering structure quantity, which means that the incorrect operation of personnel has been reduced to some extent, improving the work efficiency and measurement accuracy. The purpose of this paper is to solve the problems of computational missing, computational errors, inefficiency, data loss, and repetitive system in traditional computing based on the advantages of BIM computing system, which provide a reliable basis for cost forecasting and control. At the same time, using BMI calculation system to solve the problem of steel reinforcement in construction engineering, as well as the use of personnel, the existing calculation software still needs a lot of time and energy. We proposed a comprehensive evaluation study of reinforcement calculation in domestic construction engineering BIM calculation system based on a fuzzy comprehensive evaluation. This paper first summarizes the BIM calculation system of construction engineering, uses fuzzy comprehensive evaluation system as an important evaluation index system in domestic construction engineering BIM calculation system, through the judgment of various factors affecting the actual effect of the calculation system, and uses the fuzzy evaluation system combined with a case to demonstrate the superiority of the proposed research. Therefore, through the above research and experiments, it is concluded that the research method of this paper solves many problems in the process of engineering structure reinforcement calculation and provides a good reference method for the establishment of comprehensive evaluation system of reinforcement calculation, as well as providing an effective validation for the widespread use of BIM technology in the construction industry. Finally, it is also beneficial for users to comprehensively evaluate the BIM calculation system of the construction industry and provide a basic reference condition for different industries to use and choose BIM calculation systems.

Principles of Construction and Mathematical Models of the Formation of a Solidarity Fund in an Alternative Old-Age Pension System

The basic principles of the formation of a solidary fund in the suggested old-age pension system are to establish the minimum length of service according to which a citizen has the right to an old-age pension, the implementation into the pension calculation system of the indicator "share deducted to a solidary fund" from each transfer to the personal account of the employee, so that by retirement at the age of 60 and working experience of 38 years, the pension amount was exactly equal to the amount of wages used in calculations. With a decrease in the length of service, the pension amount is reduced according to a certain rule. To implement these principles, appropriate mathematical models have been built that allow to calculate the amount of accumulated pension capital, own pension, accumulated amounts in the solidary fund, the total amount in the pension fund, etc., with any work experience, the amount of wages. Complex calculations were performed using the parameters that have developed in the practice of today. The results of the calculations are presented in tables with the corresponding comments.

Energy Consumption When Transporting Pallet Loads Using a Forklift with an Anti Slip Pad Preventing Damage

A large number of processes for transporting and handling palletized goods using a forklift in logistics centers is usually associated with an increase in pallet and load damage. Therefore, first of all, the “damage mechanism” was identified. A classic “state of the art” analysis was conducted. The paper presents the essence of the authors’ hybrid idea of:—locking the load;—while increasing the coefficient of friction between the pallet and the forks of the forklift; but so as not to compromise on the existing functionality of the forklift forks. The idea turned out to be an innovation that required intellectual property protection, hence it was not only described in a paper but also patented. It is about an extra element that is not standard on forklifts—a forklift fork attachment. The paper discusses mechanical damage to loads involving a forklift, load damage test results, anti-slip forklift attachment, computational model of the attachment, prototype, and real-world testing of the attachment on a forklift in a logistics center. Design data from the FEM calculation system, photos of:—the prototype with components,—the prototype on tests in the logistics center were made available. The paper concludes with a pallet and load damage study performed at a logistics center and an insulation panel factory. The level of accuracy of the publication is detailed enough that the reader can make the attachment on their own and, using the content of the paper, adapt it to the needs of their own logistics system.

Factors Affecting Apparel Pattern Grading Accuracy: Existing Software Solutions Comparison and Development of New Solution

Every so often, grading is not 100% accurate due to the conventional system for calculating the grading incre¬ment. The aim of this study was to develop a new calculation system of grading increment provided by different software, e.g. Lectra, Gerber, Optitex, Boke CAD etc., and to develop a new mathematical solution that enhances grading precision. For this experiment, three different spec sheets of different buyers were collected, and then combined and drawn to a solitary sketch for both front and back including all points of measures (POM) for a more easy comparison. The solutions for the presence of diagonal and curve measurements were provided with examples using various tools and techniques of different professional garment CAD software. The benefit of the new approach is not only reduced errors of grading but also guaranteed garment fit without distorting style features. However, the drawbacks of the measurement method are complicated and time-consuming. They revolve around the fact that iterative fitting and adjustments are mandatory to improve the fit before bulk production. The study revealed that this new system slightly increases calculation time, whereas the sample approval time for order execution reduces considerably.

Research on the Detection Method of Tunnel Surface Flatness Based on Point Cloud Data

The curved surface of the tunnel is symmetrical. The curved surface of the tunnel can be roughly divided into the left and right arch walls along the direction of the central axis of the tunnel. The symmetry of the tunnel needs to be analyzed when the flatness inspection of the tunnel engineering is carried out. The flatness of the initial support of the tunnel project is an important indicator of the quality inspection and acceptance of the tunnel project. The three-dimensional laser scanner (3DLS) can be used to detect its rapidity effectively. According to the points obtained by the scanner, the surface fitting method based on B-spline interpolation and the SG bar initial support value processing method are used to optimize the tunnel surface to obtain the initial degree calculation reference. Based on the method, a calculation system for the initial flatness of the tunnel based on 3DLS technology is established. At the same time, the calculation method of the overall field of view distance and the development of small blocks is proposed. Through its application and comparison with traditional methods, the analysis shows that the three-dimensional laser scanning technology is feasible in the detection of the initial branch of the tunnel, and achieves a high degree of accuracy requirements.

Análisis de la contribución segmentaria en el rendimiento de las salidas de velocidad. (Analysis of the segmental contribution in sprint start performance)

En este estudio se ha aplicado un sistema de cálculo para examinar la contribución de cinco grupos de segmentos corporales al desplazamiento horizontal del CM en las salidas de tacos y explorar su relación con la velocidad horizontal del CM al final de 0.1s y 0.312s de la fase de aceleración. Han participado 20 velocistas con récord personal en 100 m de 11,05±0,31s. Se registraron las fuerzas horizontales de reacción mediante dos plataformas de fuerzas sincronizadas a una cámara de vídeo que registraba el plano sagital del movimiento. La contribución de las piernas al final de la fase de aceleración fue del 91.2±2.4 % y la pierna libre del 8.1±1.0 %. El tronco+cabeza es el primer grupo de segmentos que comienza a contribuir al desplazamiento horizontal del CM, alcanzando el 39.3 ± 24.3 % en los primeros 0.1s. Su rápida contribución hacia delante provoca una fuerza reactiva hacia atrás que podría estar relacionada con una dorsiflexión de los tobillos de 8º±3º y 9º±3º, pierna retrasada y adelantada, respectivamente. La contribución temprana de la cabeza+tronco se ha correlacionado positivamente con la velocidad horizontal al final de la fase de aceleración (r=0.622, p=0.003), lo que confirma su importancia como indicador de rendimiento en las salidas de tacos. Abstract. In this study, a calculation system has been applied to examine the contribution of five groups of body segments to the horizontal displacement of the Center of Mass (CM) in block starts and to explore their relationship with the horizontal velocity of the CM at the end of 0.1s and 0.312s of the acceleration phase. Twenty sprinters with a personal record in 100 m of 11.05 ± 0.31s have participated. The horizontal reaction forces were recorded using two force platforms synchronized to a video camera that recorded the sagittal plane of motion. The contribution of the legs at the end of the acceleration phase was 91.2 ± 2.4% and the free leg was 8.1 ± 1.0%. The trunk + head is the first group of segments that begins to contribute to the horizontal displacement of the CM, reaching 39.3 ± 24.3% in the first 0.1s. His quick forward contribution causes a reactive backward force that could be related to an ankle dorsiflexion of 8º ± 3º and 9º ± 3º, back and front leg, respectively. The early contribution of the head + trunk has been positively correlated with the horizontal velocity at the end of the acceleration phase (r = 0.622, p = 0.003), which confirms its importance as a performance indicator in block starts.

Automation of calculations of cutting modes taking into account the wear of cubic boron nitride tools when applying solid lubricants

The effect of a solid lubricant on the wear of cubic boron nitride grinding wheels on a ceramic bond of different hardness and grain size in the processing of high-speed steel is investigated. The dependences of the change in the wear of cubic boron nitride on the parameters of the processing mode are determined. An automated calculation system is proposed to control the consumption of cubic boron nitride grinding wheels in production conditions. Keywords: solid lubricant, grinding, high speed steel, cubic boron nitride grinding wheel, consumption, wear, grinding mode. [email protected]

Teaching the Notion Conic Section with Computer

The article discusses the problem of introducing and constructing mathematical concepts using a computer. The Wolfram Mathematica 12 symbolic calculation system is used at each stage of the complex spiral process to form the notion of conic section and the related concepts of focus, directrix and eccentricity. The nature of these notions implies the use of appropriate animations, 3D graphics and symbolic calculations. Our vision of the process of formation of mathematical concepts is presented. The notions ellipse, parabola and hyperbola are defined as the intersection of a conical surface with a plane not containing the vertex of the conical surface. The conical section is represented as a geometric location of points on the plane for which the ratio of the distance to the focus to the distance to the directrix is a constant value. The lines of hyperbola and ellipse are determined by their foci. The equivalence of different definitions for conical sections is commented.