Virtual Modeling of Dynamic Loading of Glass Mould

2008 ◽  
Vol 39-40 ◽  
pp. 535-540
Author(s):  
Ivo Matoušek

In the contribution problem of dynamic loading of glass moulds is analysed. Possibilities of FEM for evaluation of tensile states initiated with temperature variations are shown on a particular case. Critical areas where cracks nucleation as a result of thermal fatigue can be expected are evaluated. Results are used for relative comparison of service life of mould with classical design and mould with optimised design (with control cooling).

2021 ◽  
Vol 2 (7 (110)) ◽  
pp. 6-14
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska

The determination of the dynamic loading of the bearing structures of the main types of freight wagons with the actual dimensions under the main operating conditions is carried out. The inertial coefficients of the bearing structures of the wagons are determined by constructing their spatial models in the SolidWorks software package. Two cases of loading of the bearing structures of the wagons – in the vertical and longitudinal planes – have been taken into account. The studies were carried out in a flat coordinate system. When modeling the vertical loading of the bearing structures of wagons, it was taken into account that they move in the empty state with butt unevenness of the elastic-viscous track. The bearing structures of the wagons are supported by bogies of models 18-100. The solution of differential equations of motion was carried out by the Runge-Kutta method in the MathCad software package. When determining the longitudinal loading of the bearing structures of wagons, the calculation was made for the case of a shunting collision of wagons or a "jerk" (tank wagon). The accelerations acting on the bearing structures of the wagons are determined. The research results will help to determine the possibility of extending the operation of the bearing structures of freight wagons that have exhausted their standard service life. It has been established that the indicators of the dynamics of the load-carrying structures of freight wagons with the actual dimensions of the structural elements are within the permissible limits. So, for a gondola wagon, the vertical acceleration of the bearing structure is 4.87 m/s2, for a covered wagon – 5.5 m/s2, for a flat wagon – 5.8 m/s2, for a tank wagon – 4.25 m/s2, for a hopper wagon – 4.5 m/s2. The longitudinal acceleration acting on the bearing structure of a gondola wagon is 38.25 m/s2, for a covered wagon – 38.6 m/s2, for a flat wagon – 38.9 m/s2, for a tank wagon – 27.4 m/s2, for a hopper wagon – 38.5 m/s2. This makes it possible to develop a conceptual framework for restoring the effective functioning of outdated freight wagons. The conducted research will be useful developments for clarifying the existing methods for extending the service life of the bearing structures of freight wagons that have exhausted their standard resource


2018 ◽  
Vol 7 (4.3) ◽  
pp. 147
Author(s):  
Martynov I.E ◽  
Trufanova A .V ◽  
Petukhov V.M ◽  
Ischenco V.M ◽  
Kladko N.S

The possibility of increasing the service life of 18-100 three-piece bogies by using taper bearing units with different types of adapters is considered in the article. The main task is the need to increase the longevity of the running parts of freight cars by reducing their dynamic loading. The solution of this problem is possible by improving the axle boxes. To determine possible design solutions, an analysis was made of modern domestic and foreign designs of bogies using bearing assemblies with adapters and three types of adapters with the highest quality indicators, namely the half-box of the 18-7020 bogie, adapter with elastic packing and adapter of the 18-4129 bogie. Three models of adapters were investigated using the finite-elements method, which, in accordance with reported manufacturer’s data, have high reliability index and can provide equal load distribution between bearing systems rollers. The results of mathematical simulation suggest that the forces applied to the bearing systems rollers largely depend on the adapter design. Furthermore, the studied adapter designs are not acceptable and require further designing.  


2021 ◽  
Vol 20 (2) ◽  
pp. 97-104
Author(s):  
Yu. I. Kondrashov ◽  
E. N. Ermilova ◽  
A. N. Vidyaskina

The article discusses an experimental study of the influence of the valve drive type on the dynamic loading and service life of valve seals of units. The results of research of the modes of closing of piston valves and bellows valves at different response speeds are presented. The differences in the amplitude characteristics of repeated impact, arising from the rapid return motion of the valves trim, in the piston and bellows versions of the valve are established. The influence of the operating mode on the service life in both versions of the valve design was assessed, and pressurized leakage tests were also carried out.


2013 ◽  
Vol 677 ◽  
pp. 236-240
Author(s):  
Yu Sheng Wang ◽  
Wen Xuan Ma ◽  
Ming Li ◽  
Hao Jin

Cylinder cover is an important component of the engine. It is damaged by low cycle thermal fatigue, high cycle thermal fatigue and creep in operation. Thus, the life and reliability of the cylinder cover are important criteria for engines. The temperature field and stress field of the cylinder cover are computed by the sequentially coupled analysis method: the elastic strain, plastic strain and creep strain of the dangerous point on the cylinder cover are analyzed in ten startup-working-shut down cycles; and it is proved in theory that low cycle thermal fatigue is the primary factor affecting the service life of the cylinder cover and the startup time of the engine is an appropriate parameter to estimate the life of thecylinder cover. The creep has little influence on the stress amplitude, and makes the mean stress increased. The relaxation is coexisting with creep in high temperature; it reduces the increase speed of mean stress. After finite cycles, the mean stress tends to constant gradually. Therefore, the creep-fatigue interaction can equal to thermo-mechanical fatigue whose stress amplitude and mean stress are constant. At last, the mean service life of cylinder is predicted.


2020 ◽  
Vol 70 (338) ◽  
pp. 219
Author(s):  
R. Bustamante ◽  
P. Vázquez ◽  
P. Rodríguez-Monteverde ◽  
J. Monjo

The advanced condition of deterioration of the column’s bases of the courtyard of the Bishop’s Palace of Tarazona (Spain) built in the middle of 16th century required its restoration with Aragonese alabaster. Thus, adapted ageing tests were developed to simulate the environmental conditions in which the stones were and will be exposed. These tests were thermal fatigue by temperature variations, acid rain and water stagna­tion by immersion tests and a combination of both agents of decay. The results indicated that alabaster did not experimented deformation after thermal fatigue but a progressive dehydration to bassanite. This process entailed an increase of porosity and consequently a loss of structural properties. The dissolution was measured as a lineal weight and volume loss while porosity and capillary uptake remained stable. The conclusions of this study establish the importance of restoration protocols to maintain the alabaster integrity when used and exposed to rainwater and insolation.


2021 ◽  
Vol 10 (1) ◽  
pp. 1-10
Author(s):  
Virgil Florescu ◽  
Ștefan Mocanu ◽  
Ancuța Neagu ◽  
Cristina Sescu-Gal

Abstract Estimating the remaining service life of a forklift for an objective reference is not only a requirement of the applicable legislation but also represents a challenge for specialized technical staff. It is well known that the first fatigue failure element of a forklift is its fork. A simulation using the SolidWorks suite and its result is presented in this article. It allows the identification of critical areas of fatigue failure. Based on the design of the subassembly and the loading scheme of the original product, the model under analysis with finite element was made on a 1: 1 scale. The filet areas also required a comparative analysis of the results obtained depending on the choice of mesh and discretization element. Starting from the mechanical properties of the material as well as the association with the characteristic fatigue yield curves (Wohler), a method for estimating the remaining service life of the structure is proposed. The aspect related to obtaining exact results without an excessive consumption of computing resources was also taken into account.


1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.


Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.


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