Influence of Scanning and Building Strategies on the Deformation Behavior of Additively Manufactured AlSi10Mg: CPFEM and Finite Element Studies

Aniket Chakrabarty,Pritam Chakraborty,Roopam Jain,Vivek Kr. Sahu,N. P. Gurao,H. N. Bar,Niloy Khutia 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

A novel computational framework has been presented in this work for understanding the mechanical deformation behaviorin additively manufactured parts. AlSi10Mg parts were additively manufactured and investigated for effects on microstructuredue to changes in process parameters. The morphological characteristics of the printed parts were assessed, and 2Dstatistically equivalent representative volume elements (SERVEs) were created and analyzed for deformation under tensioncomputationally with crystal plasticity finite element method (CPFEM) with a combined MATLAB and ABAQUS interactiveframework. For assessing the CPFEM parameters, an interactive ABAQUS and MATLAB environment was implementedusing MATLAB’s genetic algorithm (GA) toolbox. Various results like von Mises stress distribution, maximum in-planestress distribution, and L2-norm of Green Lagrange’s strain were compared, and it was found that the vulnerability of thestructures is related to the change in process or build parameters. CPFEM analyses on 3D microstructures generated throughDREAM. 3D further confirmed the validity of results for CPFEM in 2D. The developed 2D framework also predicted thetexture that correlated well with the tension test findings. Parallely, a finite element framework was developed to study thelocalization effects on AM specimens due to the presence of pores. This work has reported two separate viewpoints in termsof porosity and microstructure.

Clival lesion incidentally discovered on cone-beam computed tomography: A case report and review of the literature

Aniket B. Jadhav,Aditya Tadinada,Kandasamy Rengasamy,Douglas Fellows,Alan G. Lurie 대한영상치의학회 2014 Imaging Science in Dentistry Vol.44 No.2

An osteolytic lesion with a small central area of mineralization and sclerotic borders was discovered incidentally in the clivus on the cone-beam computed tomography (CBCT) of a 27-year-old male patient. This benign appearance indicated a primary differential diagnosis of non-aggressive lesions such as fibro-osseous lesions and arrested pneumatization. Further, on magnetic resonance imaging (MRI), the lesion showed a homogenously low T1 signal intensity with mild internal enhancement after post-gadolinium and a heterogeneous T2 signal intensity. These signal characteristics might be attributed to the fibrous tissues, chondroid matrix, calcific material, or cystic component of the lesion; thus, chondroblastoma and chondromyxoid fibroma were added to the differential diagnosis. Although this report was limited by the lack of final diagnosis and the patient lost to follow-up, the incidental skull base finding would be important for interpreting the entire volume of CBCT by a qualified oral and maxillofacial radiologist.

Mean Drop Size Measurements with LSD, PDIA and PDA Techniques in an Airblast Spray

( Aniket P. Kulkarni ),( Vivek K. Dhimole ),( D. Deshmukh ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

The present paper compares the drop sizing measurements from PDIA (Particle Droplet Imaging Analysis) and Laser Sheet Drop sizing (LSD) with that of Phase Doppler Anemometry (PDA). Sauter Mean Diameter (SMD) measurements are performed in airblast sprays with GLR 1-4. PDIA measurements are performed at various axial and radial locations to obtain spatially resolved SMD measurements. In LSD measurements, ratio of Mie and PLIF signal is calibrated using PDIA technique at spray periphery to get quantitative planar SMD distribution. The radial SMD profiles from PDIA and LSD technique are compared to those of PDA measurements of Simmons et al [Atomization and Sprays, 20(9):821-835, 2010, DOI: 10.1615/AtomizSpr.v20.i9.60]. The experimental conditions, (e.g. airblast atomizer, air flow rate, liquid flow rate and measurement locations, etc.) used in PDIA and LSD measurements, are same as that of PDA measurements for a reliable comparison. It is observed that LSD and PDA measurements are in good agreement at most of the measurement locations. The PDIA results showed consistently higher values of SMD than that of PDA and LSD measurements. This difference between PDIA and other two techniques is significant along the spray axis. This disagreement can be attributed to the limitation of PDIA technique to measure droplets smaller than 10 ㎛ diameter. Presence of a large number of smaller droplets can be identified in Mie images, which shows strong signal along the spray axis. Hence, PDIA technique needs further improvements when atomizing spray consists of a large number of droplets with diameter less than 10㎛. Further, it is observed that LSD technique provides a reliable quantitative SMD distribution than that from PDIA measurements in fine atomizing sprays.

Study of the Effect of Two Separate Tilt Angles of Laser Scanning Lines on the Microstructure and Mechanical Properties in Direct Metal Laser Sintered AlSi10Mg Alloy

Aniket Chakrabarty,Vivek Kumar Sahu,Anindya Das,Shreya Mukherjee,Nilesh Prakash Gurao,Pritam Chakraborty,Himadri Nandan Bar,Niloy Khutia 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.1

The scanning strategy has a measurable impact on the grain size and growth direction of the produced parts in powder bedfusion. Tilting of the laser scan lines by 67° is a default procedure applicable to PBF machines for obtaining maximumvariability in the direction of melt pools. In this work, AlSi10Mg parts were produced through direct metal laser sinteringwith two diferent scanning strategies. In the frst strategy, the scanning lines were not tilted in between layers while in thesecond strategy, the scanning lines were tilted by 67°. The microstructures of the as-deposited alloys for the two strategieswere evaluated by state-of-art characterization methods like scanning electron microscopy, electron backscatter difraction(EBSD), X-ray computed tomography (X-ray CT), and X-ray difraction. Monotonic tensile tests were hence conducted inboth categories. Greater tensile strength was demonstrated by the specimens with no tilting of the scan lines while the specimens produced with a 67° tilt manifested greater elongation. Grain morphology characterized by EBSD studies suggestedan inhomogeneity in grain size for the specimens with no tilting of the scan lines. This had primarily attributed to the earlyfailure of the same. It was also found out that the preferred growth direction of grains in AlSi10Mg was hindered by tiltingthe scan lines by 67°. X-Ray CT studies and Kocks–Mecking Analysis explained the deformation and hardening behaviorof both the types in the view of porosity and structural defects.

Chronic osteitic rhinosinusitis as a manifestation of cystic fibrosis: A case report

Aniket B. Jadhav,Alan G. Lurie,Aditya Tadinada 대한영상치의학회 2014 Imaging Science in Dentistry Vol.44 No.3

A 28-year-old male patient with a history of cystic fibrosis (CF) was referred to the University of Connecticut School of Dental Medicine for an evaluation of a cystic lesion in the right maxilla using cone-beam computed tomography (CBCT). CF is an autosomal recessive disease characterized by an abnormal production of viscous mucus, affecting the mucociliary clearance. The CBCT scan revealed a large cystic lesion in the right maxilla extending from the right maxillary second molar to the midline in the region of the right central incisor with a significant buccal expansion. Further evaluation revealed complete opacification of the paranasal sinuses with medial bulging of the lateral maxillary sinus walls. The maxillary and sphenoid sinuses also appeared hypopla tic. The peculiar finding seen in this case was the presence of marked sclerosis and an increase in the thickness of the adjacent bony framework. This report aimed to describe the common sinonasal findings associated with CF and its underlying pathophysiology.

Robotics Education : Simulation of 6-DOF arm (KOBOKER) in ROS

Aniket Gupta,Manuj Trehan,Seul Jung 대한전자공학회 2019 대한전자공학회 학술대회 Vol.2019 No.6

Crack Propagation Analysis of Synthetic vs. Steel vs. Hybrid Fibre-Reinforced Concrete Beams Using Digital Image Correlation Technique

Aniket B. Bhosale,S. Suriya Prakash 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.6

Improvement in fracture behaviour of fibre-reinforced concrete (FRC) due to the inclusion of various types and combinations of fibres is widely reported. The fracture behaviour of FRC needs to be fully understood for the optimum use of these fibres in structural elements. Fracture behaviours of synthetic fibre-reinforced concrete (SynFRC), hybrid fibre-reinforced concrete (HFRC) and steel fibre-reinforced concrete (SFRC) are investigated in this study using digital image correlation (DIC) technique. This work focuses on improvement in the structural performance of FRC through a comprehensive study of the change in the crack length, crack opening and fracture process zone (FPZ) due to different fibres addition and their combinations. Three distinct fibre dosages of 0.50%, 0.75%, and 1.00%, of macro-polyolefin fibres, hooked end steel fibres and their hybrid combination are regarded as research parameters. Test outcomes indicate that HFRC offers higher post-cracking resistance when compared to SynFRC. SFRC showcases superior fracture performance than that of HFRC and SynFRC. Full-field strain measurements from DIC are used to measure the crack openings at different load levels during the fracture tests. Results of DIC analysis show good agreement with experimental measurements. Continuous monitoring of strain contours using DIC reveals the effective engagement of fibres along the depth at higher dosages for HFRC when compared to that of SynFRC. Also, HFRC had longer cracks than SFRC at a particular load.

Reformation of mistuned blade profile with a novel device offering multiple point loads

Aniket Anil Hase,Jen-Yuan Chang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4

Propeller blade manufacturing and operation becomes challenging due to unavoidable casting failures and operational errors. The existing developed patented devices are found to be inefficient in performing reformation of defected blades. Thus, the motive of this research is to develop an innovative approach to overcome the flaws associated with production and operation. Inspired by pin-art boards to form 3-dimensional (3D) shapes, a new model for blade reformation is proposed and examined in this paper. More specifically, the presented innovative device relates to method for reshaping the blade profile to achieve the desired pitch by implementing multiple point loadings over the propeller blades. Along with the device, a hybrid theoretical model was developed, validated and compared with experimental measurements and numerical finite element analyses (FEA). The results have demonstrated its capability in achieving the optimum results under given conditions, signifying its feasibility in smart and advanced manufacturing of blade reformation.

A New Perspective to Stable Marriage Problem in Profit Maximization of Matrimonial Websites

( Aniket Bhatnagar ),( Varun Gambhir ),( Manish Kumar Thakur ) 한국정보처리학회 2018 Journal of information processing systems Vol.14 No.4

For many years, matching in a bipartite graph has been widely used in various assignment problems, such as stable marriage problem (SMP). As an application of bipartite matching, the problem of stable marriage is defined over equally sized sets of men and women to identify a stable matching in which each person is assigned a partner of opposite gender according to their preferences. The classical SMP proposed by Gale and Shapley uses preference lists for each individual (men and women) which are infeasible in real world applications for a large populace of men and women such as matrimonial websites. In this paper, we have proposed an enhancement to the SMP by computing a weighted score for the users registered at matrimonial websites. The proposed enhancement has been formulated into profit maximization of matrimonial websites in terms of their ability to provide a suitable match for the users. The proposed formulation to maximize the profits of matrimonial websites leads to a combinatorial optimization problem. We have proposed greedy and genetic algorithm based approaches to solve the proposed optimization problem. We have shown that the proposed genetic algorithm based approaches outperform the existing Gale-Shapley algorithm on the dataset crawled from matrimonial websites.

Multiple intraosseous cervical pneumatocysts: A case report of a rare incidental finding on cone-beam computed tomography

Aniket B. Jadhav,Sangeetha Gajendran Sarah,Robert Cederberg,Aditya Wagh,Sudarat Kiat-amnuay 대한영상치의학회 2018 Imaging Science in Dentistry Vol.48 No.3

This report presents a case of cervical pneumatocysts as an incidental finding on cone-beam computed tomography. Pneumatocysts are gas-containing lesions of unknown etiology. They usually present in the ilium or sacrum, adjacent to the sacroiliac joint. In the literature, 21 case reports have described cervical pneumatocysts. Cervical pneumatocysts should be differentiated from other lesions, such as osteomyelitis, osteonecrosis, and neoplasms, as well as post-traumatic and post-surgical cases. Computed tomography, cone-beam computed tomography, and magnetic resonance imaging are appropriate tools to diagnose cervical pneumatocysts.