Research on the fatigue strength of self-piercing riveting by computer simulation

2021 ◽  
Vol 1 (7 (109)) ◽  
pp. 6-13
Author(s):  
Sergii Panchenko ◽  
Oleksij Fomin ◽  
Glib Vatulia ◽  
Oleksander Ustenko ◽  
Alyona Lovska

This paper reports a study into the dynamic loading and strength of an improved carrying structure of the platform car. A special feature of the car is the presence of elastic elements in the main longitudinal beams of the frame. This could improve the fatigue strength of the carrying structure of the platform car under operational modes. Mathematical modeling was carried out to determine the dynamic load on the carrying structure of the platform car. The fluctuations of bouncing were taken into consideration. It has been established that the vertical acceleration of the carrying structure of the platform car without cargo is about 2.0 m/s2 (0.2 g). In this case, the vertical accelerations that act on the carrying structure of the platform car are lower by 15 % as compared to the prototype wagon. The main indicators of strength of the bearing structure of the platform car have been determined. The calculation was carried out using a method of finite elements employing the software suite SolidWorks Simulation (France). When compiling the estimation scheme, it was taken into consideration that the carrying structure of the platform car was loaded with four containers the size of 1SS. In this case, the maximum equivalent stresses occur in the region of interaction between a pivot beam and spreads and are 254.0 MPa. That warrants the strength of the carrying structure of the platform car. The numerical values of acceleration of the carrying structure of the platform car have been determined, as well as the fields of their location, by applying computer simulation. The fatigue strength and oscillation eigenfrequencies in the carrying structure of the platform car have been investigated; their designed service time has been estimated. The reported research would contribute to building innovative structures of platform cars, as well as to improving the efficiency of combined transportation.


Author(s):  
Kiyomichi Nakai ◽  
Yusuke Isobe ◽  
Chiken Kinoshita ◽  
Kazutoshi Shinohara

Induced spinodal decomposition under electron irradiation in a Ni-Au alloy has been investigated with respect to its basic mechanism and confirmed to be caused by the relaxation of coherent strain associated with modulated structure. Modulation of white-dots on structure images of modulated structure due to high-resolution electron microscopy is reduced with irradiation. In this paper the atom arrangement of the modulated structure is confirmed with computer simulation on the structure images, and the relaxation of the coherent strain is concluded to be due to the reduction of phase-modulation.Structure images of three-dimensional modulated structure along <100> were taken with the JEM-4000EX high-resolution electron microscope at the HVEM Laboratory, Kyushu University. The transmitted beam and four 200 reflections with their satellites from the modulated structure in an fee Ni-30.0at%Au alloy under illumination of 400keV electrons were used for the structure images under a condition of the spherical aberration constant of the objective lens, Cs = 1mm, the divergence of the beam, α = 3 × 10-4 rad, underfocus, Δf ≃ -50nm and specimen thickness, t ≃ 15nm. The CIHRTEM code was used for the simulation of the structure image.


2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.


1978 ◽  
Vol 23 (9) ◽  
pp. 649-650
Author(s):  
ARTHUR M. FARLEY
Keyword(s):  

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