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Abstract: The plate heat exchanger (PHE) is a component that provides heat to be transferred from hot water to domestic cold water with-out mixing them with high efficiency. Over the lifetime of the PHE, cyclic pressure acts on the brazing points and the plates, andthis can lead to fatigue failure. The fatigue behaviour of the PHE, designed by using copper-brazed 316L (also known as 1.4404) stainless steel, was investigated by performing fatigue tests to obtain the S-N curve of the analysed brazed joint. The fatigue tests were performed on a Vibrophore 100 testing machine under the load ratio R= 0.1 for different values of calculated ampli-tude stress. Based on the obtained experimental results, an appropriate material model of the analysed brazed joint was created, which was validated with a numerical calculation in the framework of a program code Ansys. A validated material model canthen be used for the subsequent numerical analysis of the PHE.
Keywords: plate heat exchanger, brazed joint, fatigue, experimental testing
Published in DKUM: 10.04.2025; Views: 0; Downloads: 4
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Abstract: Abstract In the proposed study, the fatigue analysis of an axisymmetric chiral cellular structure and its modified form, made of stainless steel 316L, is carried out. The main goal of the original structure geometry was to absorb as much mechanical energy as possible with its auxetic behaviour. However, it was found through testing that its response could be improved by modifying the thickness of the struts through the structure. Representative models for the original and modified geometries were generated using a script adapted for this numerical simulation. Three different types of displacement in the shape of sine waves were used to load the structures. A hexagonal mesh was assigned and determined by convergence analysis. An existing material model with the necessary LCF parameters was assigned in the computational analyses. The data from multiple simulations were recorded and presented in graphs that showed how the fatigue life of the structures changed depending on the level of strain. We also analysed stresses and plastic deformations that occur in the structures. The results showed that, despite a better stress distribution, the fatigue life of the optimised structure was shorter in all cases.
Keywords: cellular structures, chiral structures, fatigue, strain-life approach, numerical analysis
Published in DKUM: 10.01.2025; Views: 0; Downloads: 8
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Abstract: V magistrski nalogi je predstavljeno konstruiranje protivlomnih avtomatskih drsnih vrat z oznako pl330b. Nova serija protivlomnih avtomatskih drsnih vrat pl330 podjetja Doorson združuje dobro izolativnost, varnost in eleganten dizajn. Ker pa se je na trgu pojavila želja po vratih z boljšimi varnostnimi lastnostmi, smo se znotraj podjetja odločili za razvoj serije pl330b. Ta serija ima ojačano konstrukcijo, dodatne zaklepe in dosega varnostni standard RC3. Naš cilj je bil ustvariti vrata, ki bodo funkcionalna, estetsko dovršena in odporna proti vlomom, s čimer bomo ostali korak pred konkurenco in zadovoljili potrebe naših strank.
Keywords: Avtomatska drsna vrata, konstruiranje, protivlomnost, prototip, testiranje
Published in DKUM: 19.09.2024; Views: 0; Downloads: 0
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Keywords: aluminium alloys, rolling direction, high-cycle fatigue, fracture analysis
Published in DKUM: 04.04.2024; Views: 183; Downloads: 18
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Abstract: The plate heat exchanger (PHE) is a component that provides heat to be transferred from hot water to domestic cold water without mixing them with high efficiency. Over the lifetime of the PHE, cyclic pressures act on the brazing points and the plates, and this may lead to fatigue failure. The fatigue behaviour of the PHE, designed using copper-brazed 316L stainless steel, was investigated in this study. First, the fatigue tests under the load ratio R = 0.1 were performed on the Vibrophore 100 testing machine to obtain the S-N curve of the analysed brazed joint. Based on the obtained experimental results, an appropriate material model of the analysed brazed joint has been created, which was validated with numerical calculation in the framework of a program code Ansys. A validated material model was then used for the subsequent numerical analysis of PHE. In order to carry out a numerical calculation using the finite element method (FEM), a three-dimensional model of the heat exchanger was created based on the previous scanning of PHE-geometry. Thereafter, the geometry was parameterised, which allowed us to perform parametric simulations (monitoring different responses depending on the input geometry). Numerical simulations were carried out in the framework of the Ansys 2023-R1 software, whereby the obtained results were analysed, and the responses were appropriately characterised according to previously determined load cases.
Keywords: brazed joint, fatigue, experimental testing, computational analyses, heat exchanger
Published in DKUM: 31.01.2024; Views: 316; Downloads: 64
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