Strojniški vestnik – Journal of Mechanical Engineering最新文献

{"title":"Study of Influential Parameters of the Sphere Indentation Used for the Control Function of Material Properties in Forming Operations","authors":"Roman Satošek, M. Valeš, T. Pepelnjak","doi":"10.5545/sv-jme.2019.6312","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6312","url":null,"abstract":"The uncertainties of modern, adaptable sheet metal forming systems are classified into model errors and disturbances. To improve the control of production, disturbances in the forming process need to be reduced. For this purpose, a new data flow system was introduced. It connected the data flow of all influencing material parameters into the “material property control function”. To control on-line the forming production line and acquire necessary material data, an indentation test was implemented. The main parameters to follow in this test are pile-up or sink-in values after the embossing of the ball-shaped tool into the material where the innovative approach of fully anisotropic material description was used. To set-up an optimal indentation test, parametric studies were performed with material data of AW 5754-H22. Finite element simulations were used to evaluate the influences of indenter diameter, contact friction and forming history of used the material. Fully anisotropic material behaviour was considered. Novel to this approach were a) the linking of the linear correlation of pile-up with the indentation depth described by gradient k, and b) the linking of gradient k with different pre-strains by a new power function.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127596042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studying the Effect of Thermal Fatigue on Multiple Cracks Propagating in an SS316L Thin Flange on a Shaft Specimen Using a Multi-Physics Numerical Simulation Model","authors":"Fariha Mukhtar, F. Qayyum, H. Elahi, M. Shah","doi":"10.5545/sv-jme.2019.6073","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6073","url":null,"abstract":"After more than a decade of research on thermal fatigue cracking in nuclear reactor components, the science remains incomplete. It is essential to understand the crack propagation behaviour and the influence of multiple cracks on the fatigue life of a component due to thermal fatigue load. Accurate numerical simulation modelling can help in better understanding the influence of different factors on failure propagation. In this research, a finite element-based numerical simulation model has been developed using ABAQUS commercial software to obtain insight into crack propagation and crack arrest in an SS316L thin flange on shaft specimen; the assembly is cooled internally, and cyclic thermal loading is applied on the flange rim. The experiment was carried out on a specially designed rig using an induction coil for heating the outer rim. Thermocouples were attached radially on the rim to collect detailed temperature profiles. Real-time temperature-dependent elastic-plastic material data was used for modelling. The boundary conditions and thermal profile used for the numerical model were matched with experimental data. The stresses responsible for crack initiation, the effect of crack number and crack lengths on stresses, energy absorbed at the crack tip after every thermal cycle and the threshold values of cracks are evaluated in the current work. The obtained simulation results were validated by comparing experimental observations. The developed simulation model helps in better understanding the evolution of stresses and strains in uncracked and cracked SS316L discs mounted on a flange due to thermal cycling. It also helped in better understanding the crack propagation behaviour and the evolution of energy release at crack tips. Such a model can help future researchers in designing components undergoing thermal fatigue loading, for example, in nuclear power plants.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122072924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Assessment of Turbulence Convective Heat Transfer and Pressure Drop in Annuli using Nanoporous Graphene non-Newtonian Nanofluid","authors":"S. Ghanbari, K. Javaherdeh","doi":"10.5545/sv-jme.2019.6035","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6035","url":null,"abstract":"In designing equipment such as heat exchangers, heating and cooling systems, it is of great importance to provide higher convective heat transfer coefficients. Techniques aimed at enhancing heat transfer can increase the thermal efficiency of such industrial devices while minimizing the cost and size. One of the solutions specified for this problem is the utilization of nanomaterials. To prepare nanofluids, nanoparticles are dispersed in an appropriate base solution which forms a suspension [1] to [3]. The initial works on the formation of nanofluids were concentrated on using metal and metal oxide nanomaterials [4]. In this respective, Heris et al. [5] researched the effect of using Al2O3/water nanofluid on convective heat transfer from which it was found that by adopting 2.5 vol.% to 3 vol.% nanoparticles, the maximum increment of heat transfer is acquired. In another research, Patel et al. [6] showed that when a mixture of 11 % Au and Ag nanoparticles are used, thermal conductivity is augmented by about 21 %. Moreover, as reported by Zarringhalam et al. [7], by using CuO/water nanofluid in forced turbulent convection in two uniaxial tubes, heat transfer is increased by up to 57 % for the sample containing 2 vol.% nanoparticles. In addition, in some relative reviews [8] to [10], thermophysical properties of different nanofluids were compared and discussed, and the effect of each nanofluid on heat transfer capability of the industrial equipment was studied. In different studies, convective heat transfer of various nanofluids has been investigated in laminar [11] and [12] and turbulent [13] flow regimes. After using the metal and metal oxides, researchers started to use carbonaceous nanomaterials, which possessed higher thermal conductivity [14] and [15]. Among these efforts, Amrollahi et al. assessed the effect of multiwall carbon nanotubes on the convective heat transfer coefficient in laminar and turbulent flows [16]. For 0.1 wt.% nanoporous graphene in a circular tube, 34 % increment of convective heat transfer was obtained by Naghash et al. [17] in which the laminar flow regime was considered. Moreover, Amiri et al. [18] studied the thermophysical properties of the nanofluid prepared with functionalized graphene. They showed that the ethylene glycol-functionalized graphene in the mixed solution of water and ethylene glycol, the thermal conductivity was enhanced by Experimental Assessment of Turbulence Convective Heat Transfer and Pressure Drop in Annuli using Nanoporous Graphene Non-Newtonian Nanofluid Ghanbari, S. – Javaherdeh, K. Shahin Ghanbari – Kourosh Javaherdeh* University of Guilan, Faculty of Mechanical Engineering, Iran","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121128814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuzzy Hybrid Method for the Reconstruction of 3D Models Based on CT/MRI Data","authors":"Mario Šokac, D. Vukelić, Ž. Jakovljević, Z. Santosi, M. Hadzistevic, I. Budak","doi":"10.5545/sv-jme.2019.6136","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6136","url":null,"abstract":"Image analysis plays a vital role in modern computeraided systems. Images can be obtained from different modalities, such as cone beam computed tomography (CBCT), magnetic resonance imaging (MRI), positron emission tomography (PET), singlephoton emission computed tomography (SPECT), ultrasound, etc. These can provide three-dimensional (3D) image datasets that contain accurate information for the generation of surface 3D models, even when compared to optical 3D digitizing methods [1]. Surface 3D models are a very useful resource for accurate diagnosis, but also for further action such as preparation of surgeries, designing different types of implants, etc. The most critical step for the generation of a surface 3D model is the accurate segmentation for extracting objects of interest from the surroundings, thus enabling 3D surface reconstruction [2] and [3]. Information acquired from medical images has a significant impact on proper diagnosis and treatment. For this purpose, the segmentation of medical images is performed, which can be either manual or automatic [4]. Nowadays, due to the large amount of data obtained using medical imaging systems, methods used for semi-automatic or fully automatic segmentation are more favourable but still refer to manual results for verification and training purposes [5]. When a 2D image is acquired, some information may be lost, and this information loss degrades the image quality, and more importantly affects the accuracy of segmentation and geometry reconstruction, eventually endangering proper diagnosis. Therefore, accurate reconstruction of geometry is required and depends on several factors, including spatial resolution, which is determined by the layer thickness [6], and slice thickness, which affects loss of resolution quality on the reconstructed data [7]. Without some form of image enhancement, segmentation of medical images becomes very difficult and sometimes does not provide accurate results. This occurs as a result of the vague structures in poorly displayed medical images, or with the presence of homogenous surrounding structures. Thus, to improve the segmentation accuracy, it is necessary to preprocess image and to enhance its quality. With the breakthrough of additive manufacturing (AM) technologies in the medical field, it enabled physical fabrication of anatomical structures, which strongly Fuzzy Hybrid Method for the Reconstruction of 3D Models Based on CT/MRI Data Sokac, M – Vukelic, D. – Jakovljevic, Z. – Santosi, Z. – Hadzistevic, M. – Budak, I. Mario Sokac1 – Djordje Vukelic1,* – Zivana Jakovljevic2 – Zeljko Santosi1 – Miodrag Hadzistevic1 – Igor Budak1 1University of Novi Sad, Faculty of Technical Sciences, Serbia 2University of Belgrade, Faculty of Mechanical Engineering, Serbia","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129982822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure-borne Noise at PWM Excitation using an Extended Field Reconstruction Method and Modal Decomposition","authors":"Janez Luznar, J. Slavič, M. Boltežar","doi":"10.5545/sv-jme.2019.6115","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6115","url":null,"abstract":"Pulse-Width Modulation (PWM) represents a carrier-frequency-dependent structural excitation. The PWM’s excitation harmonics are also reflected in the air gap’s electromagnetic forces, the vibration response and the resulting structure-borne noise. The last of these can be numerically predicted with a multiphysics finite-element-analysis (FEA) containing electronic, electromagnetic, mechanical and acoustic field problems. The multiphysics FEA are precise, but computationally inefficient and consequently inadequate for parametric studies. This paper introduces a method for a fast structure-borne noise prediction at PWM excitation. The presented approach contains the Extended Field Reconstruction Method (EFRM) to handle the magnetic saturation and slotting effects in magnetics, and the modal decomposition to couple the electromagnetic and mechanical domains. Finally, the structure-borne sound power level is calculated via the vibration-velocity response. Indeed, this approach demands a pre-calculation of the basis functions and modal parameters from the FEA, but afterwards the effect of the different PWM excitation cases can be evaluated in a few seconds. The proposed method can calculate the structure-borne noise at PWM excitation accurately and is more than 104 times faster than the conventional multiphysics FEA approach.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132539339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Double layer control for AMT clutch in commercial vehicle starting: design and experiment","authors":"S. Min, Wang Hongliang, Haiou Liu, Pai Peng, Xianhui Wang, Pi Dawei, Yang Chen, Gang He","doi":"10.5545/sv-jme.2019.6144","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6144","url":null,"abstract":"","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116414207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selected Microstructural and Mechanical Properties of Open-Cell Metal Foams","authors":"W. Depczynski","doi":"10.5545/sv-jme.2019.6027","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6027","url":null,"abstract":"Iron has been used as a basic material for everyday tools and weapons since prehistoric times. After the 19th century, which saw the emergence of new technologies for the production of iron-based alloys, steel has become ubiquitous, especially in construction. Now, with dynamic changes in technology, there is a need for new classes of materials that exhibit new characteristics. Looking for inspiration and solutions to difficult problems, engineers and scientists all over the world have often used nature, the best source of knowledge. For example, Ashby [1] wrote, “When modern man builds large load-bearing structures, he uses dense solids: steel, concrete, glass. When nature does the same, she generally uses cellular materials: wood, bone, coral”. Numerous experiments have been carried out to verify concepts concerning the fabrication and application of structural sponge-like materials. Some of the first successful attempts to produce foam materials for structural purposes led to the creation of porous polymer membranes [2] and porous polymer electrolytes [3]. Much of the research in this area has focused on the fabrication of advanced metal foams [4]. Several technologies have been invented to produce metal foams with closed or open porosity, with a crystalline or amorphous structure, and with pores ranging from a micrometre to several millimetres in size [5] and [6]. These efforts have resulted in many new applications, e.g. aluminium sound absorbers, copper heat exchangers, and nickel battery electrodes. However, Arwade et al. [7] complained, “Steel is one of the most widely used engineering materials, yet today no foam using steel as the base material is commercially available”. Further research is thus essential to develop efficient and cost-effective methods to produce Fe-based foam materials with desirable properties [8] and [9]. Sintering is one of the cheapest and most efficient methods to fabricate porous iron-based materials. It is not necessary to reach the melting point of iron to obtain a desired structure; porosity is achieved by using a space holder or a foaming agent. Bekoz and Oktay [10] fabricated sintered low-alloy steel foams using the space holder-water leaching technique. Their materials had porosity ranging from 47.8 % to 70.9 %, depending on the space holder size (500 μm to 1200 μm). Murakami et al. [11] produced iron foams using CO and CO2 as foaming gases; their maximum porosity was 55 %, and an average pore was 500 μm in size. These processes, however, involved powder compaction, which had a negative effect on the material structure. The sintered porous Selected Microstructural and Mechanical Properties of Open-Cell Metal Foams Depczyński, W. Wojciech Depczyński* Kielce University of Technology, Faculty of Mechatronics and Mechanical Engineering, Poland","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123261747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue of Cellular Structures – a Review","authors":"B. Nečemer, M. Vesenjak, S. Glodež","doi":"10.5545/sv-jme.2019.6070","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6070","url":null,"abstract":"","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128362531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research of Response Difference on Coal Cutting Load under Different Cutting Parameters","authors":"L. Wan, K. Jiang, K. Gao, Q. Zeng, Xin Zhang","doi":"10.5545/SV-JME.2018.5940","DOIUrl":"https://doi.org/10.5545/SV-JME.2018.5940","url":null,"abstract":"A shearer is important equipment for coal mining, and its performance determines the efficiency of such mining. Working under complex and harsh conditions, the conical picks mounted on the shearer drum are the cutters that participate in coal mining directly and some material failures, such as heavy wear, are prone to occurring on picks. Therefore, research on strength and wear resistance on the cutter is always in progress. In terms of the contents in previous research, a wide range of factors, such as the geometric and physical parameters of conical pick [1] and [2] and structure of coal [3] and [4], often occur in research and the final results show that the cutting load can be influenced by these factors. In terms of the simulation model applied in research, the single pick cutting model and drum cutting model are widely used; the former model occupies the major proportion in research. In fact, from the perspective of pick arrangement and mounting angle, the drum cutting model is much closer to working conditions in coal mining than the single pick cutting models, which has been verified in some previous research. Wang et al. [5] studied peak cutting force under the different half-cone angle of picks, the tensile strength and brittleness index of coal and rock. Hekimoglu and Ozdemir [6] mentioned that the arrangement of cutter tools on the drum, known as tool lacing, is one of the most critical factors that have a significant influence on cutting performance and the different pick arrangements should be designed according to cutting conditions. Liu et al. [7] researched rock fragmentation processes with single and double cutters’ model in the numerical method. He concluded that the proper line spacing played an important part in cutting efficiency improvement. In a word, the line spacing and pick arrangement play a vital role in cutting performance while those parameters cannot be simulated with single pick cutting models. Therefore, the drum cutting model is the proper model that is suitable for research on cutting performance of shearer. In the coal-cutting performance research, three kinds of approaches are available: theoretical, numerical, and experimental. Menezes et al. [8] and Li et al. [9] studied the relationship between cutting parameters and cutting performance in the explicit finite element method. Wang et al. [10] and Gao et al. [11] studied tool forces in different theoretical methods. However, the experimental model of shearer is characterized by complicated structures and large volumes. Both the requirement of higher cost and Research of Response Difference on Coal Cutting Load under Different Cutting Parameters Wan, L. – Jiang, K. – Gao, K. – Zeng, Q. – Zhang, X. Lirong Wan – Kao Jiang* – Kuidong Gao – Qingliang Zeng – Xin Zhang Shandong University of Science & Technology, College of Mechanical & Electrical Engineering, China","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125322397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Brief Survey of Preparation and Heat Transfer Enhancement of Hybrid Nanofluids","authors":"A. A. Hussien, W. Al-Kouz, N. M. Yusop, M. Z. Abdullah, Ayub Ahmed Janvekar","doi":"10.5545/SV-JME.2019.6077","DOIUrl":"https://doi.org/10.5545/SV-JME.2019.6077","url":null,"abstract":"Investigation of domestic application of heat flux dissemination is in incredible request. The best strategy in getting the coolant with an ideal execution is by including particular sorts of nanoparticles to the base fluid. The utilize of nanofluids is to escalate heat transfer coefficient through the enhancement of base fluid’s thermal conductivity. An advanced coolant (Hybrid nanofluid) was delivered by blending two or more different types of nano size particles with conventional fluid. This article mainly aims to cover the recent publications in hybrid nanofluids on different aspects such as preparation, thermophysical properties, and heat transfer enhancement. In common, the culminate combination of different nanoparticle properties results in an excellent thermal conductivity and heat transfer coefficient improvement were reached up to 148% compared to the base fluid. Moreover, moderate increase on pressure drop has been detected due to presence of composite nanoparticles. In any case, the anticipated results for both thermal conductivity and viscosity values utilizing classical relationships were distinctive from the experimental results.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131839671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}