Influence Of Variable Loads Research Articles

TRANSVERSE OSCILLATIONS OF THE BEAM ON AN ELASTIC BASE IF THE BOUNDARY CONDITIONS CHANGE

The article deals with the proper transverse oscillations of a beam with free edges while the conditions of support on an elastic base change, taking into account its own weight and the influenceof the attached mass m1. The problem of determining the forces in the beam is being solved taking into account the dynamic load F(t) applied at an arbitrary point d while the conditions for the support of a part of the beam on an elastic base change.The conditions that must be taken into account while analyzing the dynamic action of the structure under the influenceof variable loads in the case of changes in the conditions of support on an elastic base are formulated.

Influence of the composition of the metal-ceramic coating on wear resistance

The work is devoted to the development of a wear-resistant coating, combining the hardly compatible properties of high hardness and plasticity. The proposed composite coating has a nickel-chrome corrosion-resistant matrix, providing high plasticity, and hardening phase Al2O3, which can significantly increase the hardness of the coating and wear resistance. The use of laser radiation to melt the coating allows to crush Al2O3 grain to 0.05 … 1.0 MкM, which significantly increases the operational properties of the coating under the influence of variable loads on the friction assembly. Investigations of the frictional properties of wear-resistant coatings PG-10N-01 + 15% A1203 weld by a laser showed that when lubricated with hydraulic fluid AMg-10, the friction coefficient paired with Br.AJN 10-4-4 at a load of 5 … 40 MPa and a sliding speed of 0.05 m / s is less than with solid electrolytic chromium. Wear rate Br. AZH 10-4-4 at a load of 10 MPa and a sliding speed of 0.25 and 1.0 m / s in friction pair with coating PG-10H-01+15%A12O3 is 14 … 20 times less than in a pair with solid electrolytic chrome coated respectively. The wear-resistant coating PG-10N-01 + 15% A12O3, weld by laser, can be an alternative to replace hard electrolytic chrome plating. The developed technology for producing wear-resistant ceramic-metal coatings with an ultrafine hardening phase can be applied to create friction pairs of heavily loaded tribocouplings assemblies. A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.

Features of calculation of steel structures of bridge cranes at variable loads

The article deals with the calculation of metal bridge cranes operating under the influence of variable loads. Requirements to static and dynamic characteristics of mechanisms of load-lifting cranes are caused by specifics of work, features of a design and operating conditions of the cranes working at variable loadings. Thus, it is proposed to perform calculations of parts of crane mechanisms for endurance, operating under non-stationary variable load, based on the principle of linear summation of damage, allowing the calculation from the point of view of the load equivalent to the entire range of operating loads.

Research of the value of linear distortion of renewable surface of part during rotary processing of bulky items without dismantling unit

The loading and unloading units and grinding mills of raw devices have internal cone type or pipe screw perceive load of incoming and outgoing material. The main part of the support assembly is a pin. Mounting seats for the pipe screws cone have traces of deformation and work hardening, while they themselves have wear of pins and deformation of the inner and outer cylindrical working surface. In the mill body, there are constantly acting dynamic forces causing vibration, which are transmitted to the stud and inner accelerating elements. Under the influence of stress and vibration, the housing spigot is in the stress-compressed state and stretched vertically and horizontally. As a result, the insertion element is deformed and weakened in the fixture. A moving element appears in the gap leading to the fact that it drops lfeedstock and under the influence of variable loads it is destroyed, as well as the seating surfaces of the insert pin member.

Combination of patch and wheel loads: Analytical approach to plate buckling

Past studies on the stability of rectangular plates under the influence of variable loads were based on assumptions of simplified stress distributions, which put the question of the accuracy of results thus obtained. The procedure of applying the exact stress functions in the problem of elastic stability of the plate with different boundary conditions under effects of patch and wheel loading is presented in this paper. Mathieu (1890) obtained the exact solution for the plane-strain state for a rectangular element for certain types of variable stresses on the boundaries. Baker at al (1993), following Mathieu.s results, analyzed the general problem of a rectangular plate loaded by completely arbitrary distributions of (normal and/or shear) stresses along the edges of the plate. Analytical approach used for determination of the critical load is based on well known Ritz energy technique. The strain energy due to bending of the plate is defined in the traditional way. On the other hand, the exact stress distribution of Mathieu.s theory of elasticity is introduced through the potential energy of the plate associated with the work done by external loads. Results for the critical load obtained by presented analytical approach are reaffirmed by numerical finite-element (FE) runs.