Rigidity of telescopic boom equipment

2021 ◽  
Keyword(s):  
Horizontal Plane ◽  
Flexural Rigidity ◽  
Hydraulic Cylinder ◽  
Analytical Models ◽  
Dynamic Coefficient ◽  
Stiffness Coefficient ◽  
Uneven Wear

As a result of the study, analytical models of the rigidity of the telescopic boom equipment in the vertical and horizontal planes were developed, which take into account: the influence of uneven intersectional vertical and horizontal gaps, the flexibility of the sliding supports, the flexural rigidity of the sections, the rigidity of the telescoping hydraulic cylinder and the lifting hydraulic cylinder. The dynamic coefficient is determined, taking into account the presence of intersectional gaps, with unsteady movement in the vertical and horizontal plane. The influence of intersectional gaps on the coefficient of dynamism and rigidity of the boom equipment taking into account the uneven wear of the sliding supports is established. Keywords telescopic boom, railway crane, stiffness coefficient, dynamic coefficient

Shear in Flexure of Fiber Composites with Different End Supports

2003 ◽  
Vol 82 (4) ◽  
pp. 262-266 ◽  
Author(s):  
K.A. Eckrote ◽  
C.J. Burstone ◽  
M.A. Freilich ◽  
G.E. Messer ◽  
A.J. Goldberg
Keyword(s):  
Flexural Rigidity ◽  
Fiber Composites ◽  
Experimental Results ◽  
Analytical Models ◽  
Beam Deflection ◽  
Fiber Reinforced Composite ◽  
Simply Supported ◽  
Aspect Ratios ◽  
Reinforced Composite ◽  
D Values

The integrity of fiber-reinforced composite (FRC) prostheses is dependent, in part, on flexural rigidity. The object of this study was to determine if the flexure behavior of uniform FRC beams with restrained or simply supported ends and various length/depth (L/d) aspect ratios could be more accurately modeled by correcting for shear. Experimental results were compared with three analytical models. All models were accurate at high L/d ratios, but the shear-corrected model was accurate to the lowest, more clinically relevant, L/d values. In this range, more than 40% of the beam deflection was due to shear.

scholarly journals A Mathematical Model of Plane-Parallel Movement of the Tractor Aggregate Modular Type

Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 454
Author(s):  
Volodymyr Bulgakov ◽  
Aivars Aboltins ◽  
Semjons Ivanovs ◽  
Ivan Holovach ◽  
Volodymyr Nadykto ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Horizontal Plane ◽  
Hydraulic Cylinder ◽  
Design Solution ◽  
Design Parameters ◽  
Power Module ◽  
Efficient Operation ◽  
Plane Parallel ◽  
Parallel Movement ◽  
The Stability

The new machine-and-tractor aggregate of a modular type, developed by us, consisting of the power and the technological modules, can significantly increase the efficiency of using the tractor when it is aggregated with a five-body plough. The new design solution for connecting these modules in a horizontal plane through a damper, consisting of a hydraulic cylinder and a throttle, allows significant increasing of the movement stability of this aggregate in a transverse-horizontal plane. To test the efficient operation of the proposed design, as well as to determine the kinematic and design parameters that provide the required level of stable movement of this modular machine-and-tractor aggregate, we carried out theoretical and experimental field investigations. For this, a new mathematical model of plane-parallel movement of the machine-and-tractor aggregate of this type was built. It was found that a change in the operating speed of this aggregate during ploughing from 1.0 to 3.0 m∙s−1 does not lead to a deterioration in the stability of the movement of either the technological or, especially, the power modules. The delay in the reaction of the power module of the machine-and-tractor aggregate of the modular type is practically invariant with respect to the change in the mode of movement of this aggregate within the range 1–3 m∙s−1. It was also found that the values of the tire slip resistance coefficients of the wheels of the power module do not have a noticeable impact upon the development of fluctuations of the disturbing moment.

The influence of strain history and strain gradient on confined concrete

1987 ◽  
Vol 14 (3) ◽  
pp. 336-341
Author(s):  
U. Ersoy ◽  
A. T. Tankut ◽  
M. Uzumeri
Keyword(s):  
Reinforced Concrete ◽  
Strain Gradient ◽  
Flexural Rigidity ◽  
Confined Concrete ◽  
Analytical Models ◽  
Repeated Loading ◽  
Strain History ◽  
Test Results ◽  
Ultimate Capacity ◽  
Concrete Confinement

This paper outlines the results of tests performed to study the effect of strain gradient, strain history, and initial precracking on the efficiency of confinement in reinforced-concrete columns. To this end, five reinforced-concrete specimens with closely spaced ties have been tested under combined flexure and axial load.Two of the specimens were used as control specimens, subjected only to a strain gradient. The remaining three specimens were precracked using different loading schemes and then tested under a combination of flexure and axial load. Two of these specimens were tested with repeated loading.The test results revealed that precracking lowered both the flexural rigidity and the ultimate capacity of the specimens. No significant differences were observed due to the type of loading used to initially crack the specimens. Repetition of loading did not seem to affect the ultimate capacity of the specimens.Comparison of the test results with four analytical models for confined concrete showed that the models that predicted the behaviour of the control specimens accurately, overestimated the capacities of the precracked specimens. The Thompson and Park concrete model accurately predicted the behaviour of the specimens tested with repeated loading. Key words: reinforced concrete, confined concrete, confinement, columns, cyclic loading, precracked column, experimental.

scholarly journals EXPERIMENTAL STUDY OF THE MOVEMENT CONTROLLABILITY OF A MACHINE-AND-TRACTOR AGGREGATE OF THE MODULAR TYPE

2020 ◽  
Vol 61 (2) ◽  
pp. 9-16 ◽  
Author(s):  
Semjons Ivanovs ◽  
Volodymir Bulgakov ◽  
V. Nadykto ◽  
Ye. Ihnatiev ◽  
S. Smolinskyi ◽  
...  
Keyword(s):  
Experimental Study ◽  
Drag Coefficient ◽  
Horizontal Plane ◽  
Hydraulic Cylinder ◽  
Basic Principles ◽  
Hydraulic Cylinders ◽  
Angle Of Rotation

he paper presents an analysis of the basic principles of formation, the properties and characteristics of a new modular energy tool, consisting of the energy and the technology modules. The purpose of this study is to assess the degree of impact of the throttle in the hydraulic line, connecting the cavity of the hydraulic cylinder, upon the controllability of the modular power tool with a mounted plough during the movement of the ploughing aggregate on the headland. As a result of the conducted tests, it was proved that increasing the controllability of the movement of the aggregate on the basis of a mobile power tool is possible by throttling one of the hydraulic cylinders that limit the mutual reciprocal rotation of the modules in a horizontal plane. Installation of the throttle modular power tool on the limiting hydraulic cylinder with a drag coefficient 1.03×106∙N∙m∙s∙rad–1 allows one to reduce two times the delay in the reaction of the relative bearing of the energy module to a change in the angle of rotation of its driven wheels.

Synergy of surface textures on a hydraulic cylinder piston

2019 ◽  
Vol 14 (4) ◽  
pp. 424-429 ◽  
Author(s):  
Ying Zhang ◽  
Liangcai Zeng ◽  
Zhenpeng Wu ◽  
Xianzhong Ding ◽  
Kuisheng Chen
Keyword(s):  
Hydraulic Cylinder ◽  
Surface Textures ◽  
Cylinder Piston

Mechanism of irregular crack-propagation in thermal controlled fracture of ceramics induced by microwave

2020 ◽  
Vol 21 (6) ◽  
pp. 610
Author(s):  
Xiaoliang Cheng ◽  
Chunyang Zhao ◽  
Hailong Wang ◽  
Yang Wang ◽  
Zhenlong Wang
Keyword(s):  
Crack Propagation ◽  
Industrial Application ◽  
Ceramic Materials ◽  
Advanced Technology ◽  
Analytical Models ◽  
Propagation Mechanism ◽  
Unstable Crack ◽  
Fracture Simulation ◽  
Initial Stage ◽  
Controlled Fracture

Microwave cutting glass and ceramics based on thermal controlled fracture method has gained much attention recently for its advantages in lower energy-consumption and higher efficiency than conventional processing method. However, the irregular crack-propagation is problematic in this procedure, which hinders the industrial application of this advanced technology. In this study, the irregular crack-propagation is summarized as the unstable propagation in the initial stage, the deviated propagation in the middle stage, and the non-penetrating propagation in the end segment based on experimental work. Method for predicting the unstable propagation in the initial stage has been developed by combining analytical models with thermal-fracture simulation. Experimental results show good agreement with the prediction results, and the relative deviation between them can be <5% in cutting of some ceramics. The mechanism of deviated propagation and the non-penetrating propagation have been revealed by simulation and theoretical analysis. Since this study provides effective methods to predict unstable crack-propagation in the initial stage and understand the irregular propagation mechanism in the whole crack-propagation stage in microwave cutting ceramics, it is of great significance to the industrial application of thermal controlled fracture method for cutting ceramic materials using microwave.

Classifying the Past: Discriminant Analysis and its Application to Medieval Farming Systems

1996 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ken Bartley
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Processing Time ◽  
Farming Systems ◽  
Frame Of Reference ◽  
Analytical Models ◽  
Successful Implementation ◽  
Medieval Period ◽  
The Past ◽  
Livestock Management

This paper discusses the need for nationally based analytical models of the medieval period. The use of cluster analysis as a method for classifying demesne farms, by the crops they grew and their livestock management, is explained. Successful implementation of cluster analysis requires both the existence of a large base sample, to permit isolation of specific groupings within the data, and access to considerable processing time. The paper concludes by demonstrating how discriminant analysis can provide an efficient and systematic way of classifying even a single manor within a national frame of reference.

Transient Property Improvement of Hydraulic Cylinder Control for Tunnel Boring Machine Using Opposite Reference Filter

2020 ◽  
Vol 140 (3) ◽  
pp. 320-325
Author(s):  
Yoshihiro Ohnishi ◽  
Takahisa Shigematsu ◽  
Takuma Kawai ◽  
Shinichi Kawamura ◽  
Noboru Oda
Keyword(s):  
Tunnel Boring Machine ◽  
Hydraulic Cylinder ◽  
Tunnel Boring
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