Wyniki wyszukiwania - BazTech

1

Analysis of the construction of the car trailer frame in terms of changing the assembly technology

Caban Jacek, Nieoczym Aleksander, Matijošius Jonas, Kilikevičius Artūras, Drozd Kazimierz

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2024

|

z. 124

47--61

EN

Car trailers are quite a popular means of transport and are offered in many versions, from single axle light trailers with a maximum permissible weight of 750 kg, through two- or more-axle specialized trailers. The issues of research car trailers focus on two directions: testing the driving properties and analysing the strength of the supporting frame system. Issues related to the construction of light trailers are often common to trailers used in agriculture or general transport. In this article, based on a mass-produced car trailer, an analysis was carried out regarding the choice in the technology of making the supporting structure consisting of a lower frame and an upper frame. The term upper frame should be understood as the structure on which the lifted load box rests. The costs of materials, assembly and technological possibilities of small-scale production were taken into account. In addition, strength analyses of the numerical models were carried out for critical areas of the frame during operation. After considering the unit costs for each of the analysed assembly technologies, it was shown that riveting would be the cheapest. However, the most suitable method of assembly is welding, as it allows the use of standard profiles.

2

Abrasive Wear Mechanisms of S235JR, S355J2, C45, AISI 304, and Hardox 500 Steels Tested Using Garnet, Corundum and Carborundum Abrasives

Szala Mirosław, Szafran Michał, Matijošius Jonas, Drozd Kazimierz

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 2

147--160

EN

Wear resistance is one of the main indicators of the reliability of machine parts. The selection of wear-resistant material should consider the operational environment and specific types of abrasive material. The steel abrasive wear resistance depends not only on its hardness and microstructure but also on the abrasive material's properties, such as hardness and particle morphology. This work aimed to determine abrasion wear mechanisms of a set of steels, i.e., S235, S355, C45, AISI 304 and Hardox 500, abraded by different types of grit i.e. garnet, corundum and carborundum. The abrasion tests were conducted using T-07 tribometer (rubber wheel method). Wear traces were examined with a scanning electron microscope (SEM), and a contact profilometer. SEM analysis revealed that apart from Hardox 500, ploughing and microfatigue were the dominant wear mechanisms. Microcutting was the main wear mechanism for Hardox 500 tested with carborundum (SiC). The highest mass loss was usually obtained for carborundum. The lowest wear resistance in garnet and carborundum was obtained for the S235JR and S235J2 steels and Hardox 500 tested with corundum. The effect of steel microstructure on the wear mechanism has been confirmed. AISI 304 austenitic steel abraded by carborundum grit, presented outstanding roughness parameters: Ra, Rz, RSm, Rk, Rvk and Rpk than other steels tested with carborundum. Steel hardness affects the morphology of the wear trace reducing the Ra and Rz roughness parameters. The effect of abrasive hardness and grain morphology on abraded surfaces has been stated. Contrary to fine grains of the hardest carborundum, coarse garnet grains caused high roughness parameters (Rk, Rpk and Rvk) determined in wear trace.

3

Modeling and Exploitation Load Tests of the Suspended Route Slings Caused by Passage of the Locomotive at Various Speed along Mining Excavation

Drozd Kazimierz, Nieoczym Aleksander

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no. 1

266--281

EN

Despite the fact that suspended monorails have been used in the mining industry for over 50 years it is necessary to continue research on the possibilities of increasing the unit mass of the transported load or the speed of people transport. The first step is to establish the exact dynamic load of suspended route’ elements and compare this value with easy to calculation static load. The objective of the research was to determine the influence of speed and direction of travel on maximum load force applied to the sling of the route in mining excavation. The research results indicated that the speed of 2 ms−1 does not significantly influence the load on the sling. Theoretical hypothesis, stating that the estimation of the force value in the sling ought to be performed using projecting on a surface perpendicular to the route was confirmed. It was also proven that in order to characterize the geometry of the sling as well as a precise analysis of its load it is necessary to employ the length and the angle of the chain in relation to the above mentioned surface. Upon employing statistical analysis of the test results, the maximum dynamic effect of the locomotive passing was determined to be 20.1 ± 2.5% of the value of the calculated static load for all slings, projected onto a plane perpendicular to the route. For a single sling, mounted on a test route section inclined at an angle of about 10°, the increase in force due to the passage of the locomotive was up to 21.0% of the static load for this sling.

4

Fractographic Assessment and FEM Energy Analysis of the Penetrability of a 6061-T Aluminum Ballistic Panel by a Fragment Simulating Projectile

Nieoczym Aleksander, Drozd Kazimierz

Advances in Science and Technology. Research Journal

|

2021

|

Vol. 15, no. 1

50--57

EN

In aviation and light vehicles, aluminum plates are often used instead of heavy shields as ballistic shields. The standard shrapnel was used in the analysis due to the fact that under hazardous conditions, the shrapnel destruction occurs more often than directly with a bullet. Analyses were performed in which the initial velocity and the angle of impact were the variables. The material of the aluminum plate (ballistic shield) with a thickness of 1 mm was divided into three-dimensional C3D4 tetragonal elements. The calculations were performed using the Johnson-Cook model for the impact at an adjustable velocity from 25 m/s to 55 m/s every 10 m/s and impact angle set between 0° and 45° in increments of 15°. Stress maps that allow observation of the plate degradation areas were placed in the plate. It was found that the penetration of the ballistic panel by the fragment under simulated conditions occurs at the initial velocity of this fragment greater than 25 m/s. The fragment simulating a projectile, hitting at a velocity of 35 m/s at an angle of not more than 15° perforates this panel. At an impact velocity of 45 m/s, perforation occurred at an impact angle of up to 30°. A further increase of the fragment’ velocity of impact on the plate resulted in its perforation even at the greatest impact angle.

5

Geometric optimization of a beam detector for a WIM system

Nieoczym Aleksander, Drozd Kazimierz, Wójcik Andrzej

Advances in Science and Technology. Research Journal

|

2018

|

Vol. 12, no. 3

233--241

EN

Weigh-in-Motion (WIM) systems are designed for weighing vehicles driving across a measurement site. Because during measurements the vehicle has to come in physical contact with the components of the system, WIM systems always use built-in sensors installed in road pavement. Each WIM system consists of force sensors placed in one, two or even several lines, perpendicular to the direction of traffic. The idea behind WIM systems is to measure the dynamic loads that the wheels of a moving vehicle exert on the road surface and, on this basis, to estimate static wheel loads as well as gross vehicle weight.