Numerical Analysis on the Key Technology in Extrusion Tapping of Internal Thread

2011 ◽  
Vol 341-342 ◽  
pp. 436-441 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao

This paper introduces the principle and characteristic of extrusion tapping of internal thread, presents the simplified mechanical model of extrusion tapping firstly. Then generalizes the key technology of extrusion tapping and their influencing law on tapping torque and thread forming quality, such as extrusion tap type, lead hole diameter, tapping speed and friction. Finally, numerical analysis on the key technology of extrusion tapping are conducted based on DEFORM-3D, the results show that the effect of lead hole diameter and friction on tapping torque are obvious, the effect of extrusion tap type and tapping speed on tapping torque are next and this effect degree is related to the stress-strain relation of workpiece material under different strain-rate closely. These researches will contribute to the right selection of workpiece material, extrusion tap type, lead hole diameter, tapping speed and lubrication of extrusion tapping of internal thread in practical manufacture.

2011 ◽  
Vol 295-297 ◽  
pp. 2636-2641 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao

Internal thread processing is an indispensable procedure in manufacture, its processing efficiency and quality become more and more important in modern manufacturing, especially in aerospace and automotive industry. Compared with the traditional process of cut tapping of internal thread, the process of extrusion tapping of internal thread possesses the following advantages: without chip, higher precision, better surface quality, better continuity of metallic, greater efficient, greater strength, longer tool life. This paper firstly introduces the current research status of extrusion tapping of internal thread, elaborates the principle and characteristic of extrusion tapping, analyzes the matal plastic flow law and thread forming characteristic during tapping, then generalizes the influencing law of the key technology on thread forming quality, such as extrusion tap type, lead hole diameter, tapping speed and friction. Furthermore, puts forward some improvement approach to reduce tapping torque and enhance forming quality of internal thread.


Author(s):  
Abhineet Singh ◽  
Sonali Mitra ◽  
S.V.H. Nagendra ◽  
Pragyan Jain

The present paper deals with the selection of airfoil profile for VAWTs which is to be installed in the college campus, located in Central India region. Both experimental and numerical analysis he been carried out for the three selected airfoils, NACA 0012, NACA 0015 & S2027. The results show a good correlation with the existing literature. Airfoil profile S2027 has been chosen which best suits our condition. 


Author(s):  
Яна Валерьевна Самиулина

В настоящей статье предпринята попытка исследовать отдельные проблемные аспекты института потерпевшего в российском уголовном процессе. В этих целях подвергнуты анализу правовые нормы, регламентирующие его процессуальный статус. Раскрываются отдельные пробелы уголовно-процессуального законодательства в сфере защиты законных прав и интересов потерпевшего. Автор акцентирует внимание на том, что совершенствование уголовно-процессуального законодательства в части расширения правомочий потерпевшего по отстаиванию своих нарушенных преступлением прав следует продолжить. На основании проведенного исследования действующего законодательства в части регламентации прав потерпевшего от преступления предлагается расширить перечень получаемых им копий постановлений, указанных в п. 13 ч. 2 ст. 42 УПК РФ. Автор предлагает включить в перечень указанной законодательной нормы право получения потерпевшим копии постановления об избрании конкретного вида меры пресечения, избранного в отношении подозреваемого (обвиняемого). Для создания действенного механизма защиты интересов потерпевших от преступления юридических лиц предлагаем ч. 9 ст. 42 УПК РФ изложить в следующей редакции: «в случае признания потерпевшим юридического лица его процессуальное право в уголовном процессе осуществляет представляющий его профессиональный адвокат». This article attempts to investigate certain problematic aspects of the institution of the victim in the Russian criminal process. For this purpose, analyzed the individual norms governing his procedural status. Separate gaps of the criminal procedure legislation in the sphere of protection of the legal rights and interests of the victim are disclosed. The author emphasizes that the improvement of the criminal procedure legislation in terms of the extension of the victim’s authority to defend his rights violated by the crime should be continued. On the basis of the study of the current legislation regarding the regulation of the rights of the victim of a crime, it is proposed to expand the list of decisions received by him, referred to in paragraph 13, part 2 of article 42 Code of Criminal Procedure. The author proposes to include in the list of the indicated legislative norm the right to receive the victim a copy of the decision on the selection of a specific type of preventive measure, selected in relation to the suspect (accused). To create an effective mechanism for protecting the interests of legal entities victims of a crime, we offer part 9 of art. 42 of the Code of Criminal Procedure of the Russian Federation shall be reworded as follows: «if a legal entity is recognized as a victim, his procedural right in criminal proceedings is exercised by the professional lawyer representing him».


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3927
Author(s):  
Joanna Taczała ◽  
Katarzyna Rak ◽  
Jacek Sawicki ◽  
Michał Krasowski

The creation of acrylic dentures involves many stages. One of them is to prepare the surfaces of artificial teeth for connection with the denture plates. The teeth could be rubbed with a chemical reagent, the surface could be developed, or retention hooks could be created. Preparation of the surface is used to improve the bond between the teeth and the plate. Choosing the right combination affects the length of denture use. This work focuses on a numerical analysis of grooving. The purpose of this article is to select the shape and size of the grooves that would most affect the quality of the bond strength. Two types of grooves in different dimensional configurations were analyzed. The variables were groove depth and width, and the distance between the grooves. Finally, 24 configurations were obtained. Models were analyzed in terms of their angular position to the loading force. Finite element method (FEM) analysis was performed on the 3D geometry created, which consisted of two polymer bodies under the shear process. The smallest values of the stresses and strains were characterized by a sample with parallel grooves with the grooving dimensions width 0.20 mm, thickness 0.10 mm, and distance between the grooves 5.00 mm, placed at an angle of 90°. The best dimensions from the parallel (III) and cross (#) grooves were compared experimentally. Specimens with grooving III were not damaged in the shear test. The research shows that the shape of the groove affects the distribution of stresses and strains. Combining the selected method with an adequately selected chemical reagent can significantly increase the strength of the connection.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 158
Author(s):  
Colin Eady

For 30 years, forage ryegrass breeding has known that the germplasm may contain a maternally inherited symbiotic Epichloë endophyte. These endophytes produce a suite of secondary alkaloid compounds, dependent upon strain. Many produce ergot and other alkaloids, which are associated with both insect deterrence and livestock health issues. The levels of alkaloids and other endophyte characteristics are influenced by strain, host germplasm, and environmental conditions. Some strains in the right host germplasm can confer an advantage over biotic and abiotic stressors, thus acting as a maternally inherited desirable ‘trait’. Through seed production, these mutualistic endophytes do not transmit into 100% of the crop seed and are less vigorous than the grass seed itself. This causes stability and longevity issues for seed production and storage should the ‘trait’ be desired in the germplasm. This makes understanding the precise nature of the relationship vitally important to the plant breeder. These Epichloë endophytes cannot be ‘bred’ in the conventional sense, as they are asexual. Instead, the breeder may modulate endophyte characteristics through selection of host germplasm, a sort of breeding by proxy. This article explores, from a forage seed company perspective, the issues that endophyte characteristics and breeding them by proxy have on ryegrass breeding, and outlines the methods used to assess the ‘trait’, and the application of these through the breeding, production, and deployment processes. Finally, this article investigates opportunities for enhancing the utilisation of alkaloid-producing endophytes within pastures, with a focus on balancing alkaloid levels to further enhance pest deterrence and improving livestock outcomes.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marshal Thakran ◽  
Meenakshi ◽  
Jitender Sharma ◽  
Charles Gilbert Martin

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.


2021 ◽  
Vol 263 (1) ◽  
pp. 4955-4961
Author(s):  
Mathieu Gontier ◽  
Barbara Romeyns

In industry segments such as automotive and industrial equipment the use of compressed porous materials is well known to improve the global acoustic performance of the complete system. Such porous materials should be designed in a specific way in order to reach a significant acoustic sealing performance at different compression rates. Unfortunately, there are no standard measurement procedures nor predefined material characteristics that allow the selection of the right material with the optimal acoustic performance. The main goal of this research is to link acoustic performance of compressed porous materials with intrinsic material characteristics using statistical techniques.


Author(s):  
Andy Dong ◽  
Alice M. Agogino

Abstract In design synthesis, engineering prototypes make an ideal representation medium for preliminary designs. Unlike parametric design wherein a pre-specified design is parametrically varied, design synthesis demands artistic creativity and engineering experience to transform the previously known components, relationships and designs into a new form. The process compels the designer to ascertain which prototypes will, in some sense, best satisfy the design task. The challenge in this assignment lies in selecting the “right” design prototype. This selection process typically entails an objective evaluation of different designs that perform the same functions or have similar intended behavior and comparing trade-offs between alternate designs. This paper introduces a multi-objective spectral optimization algorithm for the selection of design prototypes based upon their functional representations. The optimization algorithm returns an index of rank, scoring the functional similarity of the proposed design to the goal design. Two illustrative examples apply the algorithm to the selection of a heat fin and beam.


2018 ◽  
pp. 7-79
Author(s):  
S.Yu. Vdovichenko ◽  
◽  
T.D. Fakhrutdinova ◽  

The objective: depression of obstetric and perinatal complications at pregnant women with pathological increase of body weight during pregnancy on the basis of studying of clinical-functional, endocrinologic, metabolic, morphological features of condition of fetoplacental complex and development of advanced algorithm of treatment-and-prophylactic actions. Materials and methods. We conducted examination of 264 patients who consisted on the account concerning pregnancy in female consultations of Kiev. By a method of selection of 178 women were included in retrospective research and 86 – in prospective. The main group was made by 39 pregnant women with whom led individual discussions, control – 142 women, that received traditional references in female consultation. Results. Use of the algorithm improved by us allows to improve obstetric (decrease of frequency of a preeclampsia by 12.3%; anomalies of a patrimonial deyalnost for 8.4%) and perinatal outcomes (depression of level of an asphyxia at a delivery for 9.4% and post-natal adaptation for 7.8%) deliveries of women with an excessive increase of body weight during pregnancy. Conclusion. The received results grant the right to recommend the algorithm improved by us for wide use in practical health care. Key words: obstetric and perinatal pathology, pathological increase of body weight, prophylaxis.


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