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Journal articles on the topic 'Straightening line'
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1
Eley, G. "Straightening the Line?" German History 25, no. 4 (October 1, 2007): 633–36. http://dx.doi.org/10.1177/0266355407082778.
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Lee, Hau Wei, Po Er Hsu, Shan Peng Pan, Tze An Liu, and Huay Chung Liou. "Applying Structured Light on Cylinder Straightness Detection Using Break Line Method." Applied Mechanics and Materials 764-765 (May 2015): 1298–303. http://dx.doi.org/10.4028/www.scientific.net/amm.764-765.1298.
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Generally after a cylindrical steel bar is made from hot forming process, its contour will look like ‘U’ or ‘wavy’ topography. The preformed steel bar after steelmaking process needs to remove the outside oxide layer by lathe or peeling machine (commonly known as stripping). As a consequence, the deformation of steel bar will cause subsequent problems, such as eccentric rotating of steel bar as the lathe is running. Although it is necessary to remove the oxide layer, the deformation will increase waste materials. To prevent the problems, a straightening machine is usually used to straighten the cylindrical steel bar before the pickling process. However, most current straightening machines cannot measure cylindrical steel bar contour on-line instantly. This study proposed a test method for measure the contour of a large cylindrical steel bar based on multi-line structured light and machine vision. Break line method were performed to measure the contour of the cylindrical steel bar. The experimental result shows that the measurement error is in the range of ±0.4 mm after calibration. The study result concludes that the proposed method can be applied to straightening machine for real-time online measurement to improve straightening efficiency.
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Yang, Mei, Chun Yan Tian, You Quan Chen, and Cheng Da Ning. "Development of the On-Line Straightness Detection System for Shafts." Applied Mechanics and Materials 490-491 (January 2014): 1592–95. http://dx.doi.org/10.4028/www.scientific.net/amm.490-491.1592.
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Aiming at the low efficiency and precision of nowadays domestic auto-straightening machine of shafts, a new kind of shafts straightness detection system is researched and developed. The supporting part of the measuring mechanism adopts the mechanical structure of auto-going-down of straightening points supporting pedestal. The whole convolute measuring system fixes on the machine tool orbit sliding table, whose movement can change the position for the straightening point and make positioning faster and more accurate. In addition, this detection system bases on applications math and builds math model by Fourier transform which can separate the elliptical error signal, straightness error signal and impulse error signal and then gained ideal straightness error of shafts.
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Han, Xue Yan, Kang Liu, and He Rong Jin. "Design of High Precision Online Sizing Cutter for PC Steel Bars." Advanced Materials Research 746 (August 2013): 520–23. http://dx.doi.org/10.4028/www.scientific.net/amr.746.520.
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Along with the development of high-rise buildings and high-speed railways, the straightness and sizing accuracy of PC steel bars is highly demanded. The addition of precision straightening process between traction and shear in the production line of PC steel bars can improve the application performance of products effectively. Moreover, the traditional shear mode is changed to realize high precision sizing and cutting purpose in high-speed production (90m/min). A straightening scheme with large deformation and equal curvature was proposed in this article, which can realize circumferential standstill locking of bars in the perpendicular straightening planes and guarantee straightening precision. Based on mechanical-electro-hydraulic integration technology, optical-mechanical-electrical sizing and conjugate cam cutting method were presented. 9/13 numerical control sizing cutter for PC steel bars is developed in the production line of PC steel bars, which has high automation, better straightening effect, and minor sizing error.
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Du, Yan Bing, Jing Tao Han, and Yong Jun Zhang. "The Development of Auxiliary Sets in Novel Cold Roll Forming Line - Continuous Mini Stretching-Bending Straighter and Roller Punching System." Advanced Materials Research 291-294 (July 2011): 1178–82. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.1178.
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Cold roll forming thin strip products occupy a rather large proportion of novel cold bending manufacturing. Conventional roller straightening could not obtain perfect straightening effects when the thickness of strip less than 1mm. On the basis of continuous roller stretcher straightening theory, we developed an area saved, high efficient strip straightening facility. At the same time, punching is also requested during the cold roll forming of strips. High quality productions can be achieved at high speed through the roller punching system, so the device is adaptive for high efficiency cold roll forming production.
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Ho, Huei Jin, David A. Ray, Abdel-Halim Salem, Jeremy S. Myers, and Mark A. Batzer. "Straightening out the LINEs: LINE-1 orthologous loci." Genomics 85, no. 2 (February 2005): 201–7. http://dx.doi.org/10.1016/j.ygeno.2004.10.016.
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KUBOKI, Takashi, Makoto MURATA, and Tetsuya SASAKI. "2238 Two roll straightening process of line materials." Proceedings of the JSME annual meeting 2005.1 (2005): 639–40. http://dx.doi.org/10.1299/jsmemecjo.2005.1.0_639.
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King, Ian W. "Straightening our Perspective: The Logos of the Line." Organization 14, no. 2 (March 2007): 225–41. http://dx.doi.org/10.1177/1350508407074226.
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Chavoshi, Seyed Ehsan, and Seyed Ebrahim Moussavi Torshizi. "Bending improvement in Spot Heating of pipes in comparison with Line Heating method." Mechanics & Industry 20, no. 4 (2019): 405. http://dx.doi.org/10.1051/meca/2019030.
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In Spot Heating, a small area of a metal part surface is heated quickly with a gas torch, laser beam, or induction coil to a temperature below the phase change temperature and then cools down. The heated area undergoes compressive plastic strain and the part gets deformed. This method is usually applied as trial and error for straightening shafts, bridge components, ship structures, etc. The conventional straightening mechanism in industries involves creating thermal gradient mechanism (TGM) and shortening. Many studies have been conducted for bending of thin pipes (at a maximum thickness of 2 mm) with the induction of “shortening” by laser. Spot Heating, despite its simplicity, results in very small deformations. The present study aims to increase the deformation in the Spot Heating method so as to extend its use in pipe straightening. To meet this goal, the shortening mechanism is developed through a thick pipe wall by optimizing the heating parameters. CFD analysis of flame flow is carried out to determine the heat flux distribution over the pipe surface. Also, the finite element method and optimization are used to analyze and raise the pipe deformation mechanism. The results indicate a considerable increase in the pipe bending which reduces the stages necessary for the pipe straightening in industries. Furthermore, the appropriate distance for combining the hot spots is also obtained. To evaluate the results, the Spot Heating test is performed, showing appropriate agreement with the simulation results.
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Miyachi, S., T. Izumi, N. Matsubara, T. Naito, K. I. Haraguchi, and T. Wakabayashi. "The Mechanism of Catheter Kickback in the Final Stage of Coil Embolization for Aneurysms: The Straightening Phenomenon." Interventional Neuroradiology 16, no. 4 (December 2010): 353–60. http://dx.doi.org/10.1177/159101991001600401.
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The catheter kickback phenomenon often occurs in the last stage of coil packing for cerebral aneurysms. This behavior is considered the result of either a lack of space in the sac or a stiff detaching zone. In order to clarify its mechanism, focused stretch-resistance (SR) coil simulation models were tested. Various commercially available SR coils were inserted into a cylinder or an aneurismal sac made from a silicone tube with a smaller than prescribed diameter. A magnified SR coil model (straight type) of fishing line was created for simulation. Numerical analysis for the changes in coil behavior were verified. All SR coils showed hardening and straightening at the last few millimeters, resulting in catheter kickback. In a magnified coil experiment, straightening was also realized when folding into a narrow cylinder. The SR line coursed in the canal of the first loops and shifted to the outside in the middle portion. Gaps among first coil pitches were enlarged on after insertion into the narrower space. Shortage of the SR line was calculated to reach a maximum of 32%. The straightening phenomenon is due to SR line shortening and subsequent condensation of pitches of the first loops at the coil end. Coil tail flexibility was lost, and the coil behaved as a stiff wire. Straightening is an important factor in the kickback phenomenon. Shorter final SR coils should be selected, and coil designs should be improved.
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Sun, Jianliang, Mengqian Sun, Yunjing Jiao, and Yanan Gao. "Study on Plate Straightening Process Based on Elastic-Plastic B Spline Finite Strip Method." Journal of Mechanics 36, no. 6 (May 7, 2020): 737–47. http://dx.doi.org/10.1017/jmech.2020.16.
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ABSTRACTAn elastic-plastic B spline finite strip method is proposed to investigate the continuous plate straightening process in this paper. First, the B spline displacement function that satisfies the boundary conditions of simply supported end and free end of the strip element is established, and then the stress-strain matrix is established. Second, the set method of total stiffness matrix based on B spline finite strip method for plate straightening problem is proposed, and the influence of nodal line number and strip elements number on the sparsity of total stiffness matrix is analyzed. Third, the loads on the strip elements are taken as linear uniform distribution, and the transformation matrix between the equivalent linear load and the actual load of the strip element is established. At last, the plate straightening simulation of 11 rolls straightening machine is made based on the elastic-plastic B spline finite strip method, the calculated results agree with the measured results, which approves that the elastic-plastic B spline finite strip method established can be applied to the plate straightening process.
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Adewole, K. K., and S. J. Bull. "Effectiveness of the Reverse Bending and Straightening Tests in Detecting Laminations in Wires for Civil Engineering Applications." Archives of Civil Engineering 59, no. 4 (December 1, 2013): 423–39. http://dx.doi.org/10.2478/ace-2013-0023.
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Abstract The reverse bending and straightening test is conducted on wires used for civil engineering applications to detect laminations which can pose a threat to the integrity of the wires. The FE simulations of the reverse bending and straightening of wires with laminations revealed that the reverse bending and straightening test is only effective in revealing or detecting near-surface laminations with lengths from 25mm located up to 30% of the wire’s thickness and may not be an effective test to detect mid-thickness, near-mid-thickness, and short near-surface laminations with lengths below 15mm. This is because wires with mid-thickness, near-mid-thickness and short nearsurface laminations will pass through the reverse bending and straightening procedures without fracturing and therefore mid-thickness, near-mid-thickness and short near-surface laminations may go undetected. Consequently, other in-line non destructive testing methods might have to be used to detect mid-thickness, near-mid-thickness and short near-surface laminations in the wires.
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Jang, Chang Doo, Toshiharu Nomoto, Dae Eun Ko, Hyun Su Ryu, and Yun Sok Ha. "Simulation of Postwelding Distortion Control of Stiffened Hull Blocks by Line Heating." Journal of Ship Research 50, no. 03 (September 1, 2006): 268–77. http://dx.doi.org/10.5957/jsr.2006.50.3.268.
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The objective of this study is to develop an analysis method to predict the reduction of welding distortion of stiffened plates by line heating. The equivalent loading method, based on the inherent strain theory, was established to analyze the heat straightening of stiffened plates. The heat input for the analysis was obtained based on experimental temperature variation curves. Temperature distributions during two- line heating process were calculated by two-dimensional heat transfer analysis using the finite element method. The degree of restraints was estimated by combining the experimental data of simple specimen and unit loading analysis. Equivalent loads were obtained by integrating the inherent strains, which were determined from the highest temperature and the degree of restraint. Finally, the equivalent loads obtained were imposed, as applied loads, on the elastic analysis to predict the reduction of welding deformation in stiffened plates. If the basic experiments for several simple cases are carried out, the proposed method can be extended to the analysis of heat straightening of welding distortion of more complicated stiffened plates and ship hull blocks.
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Okumoto, Yasuhisa, Hideharu Yanai, and Shin-ich Matsuzaki. "Angular Distortion Due to Fillet Welding and Its Straightening." Journal of Ship Production 16, no. 02 (May 1, 2000): 90–96. http://dx.doi.org/10.5957/jsp.2000.16.2.90.
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In order to increase the productivity of shipbuilding to respond to current situations such as decreasing numbers of skilled workers and aging of workers in the shipyard, mechanization and robotization have been accelerated. To apply them effectively, the current fabrication and assembling system of ship hull has to be reviewed so that the dimensional accuracy of the hull block and its components increase particularly. Accordingly, the authors had developed an "accurate production system" for the fabrication and assembly of flat block, which was based on advanced accuracy technology and modem automated machines. This report concerns the deformation due to the filet welding of longitudinals on a skin plate and its straightening; the estimation of welding deformation, especially angular distortion, and its straightening method using a press roller which was developed newly in this automated production line. In order to clarify the power of the straightening machine, non-linear FEM analysis was carried out.
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Antimonov, Aleksey, and Nadezhda Pushkareva. "Fuel Pipes Coil Drawing Line Production for Diesel Engines." Materials Science Forum 946 (February 2019): 739–43. http://dx.doi.org/10.4028/www.scientific.net/msf.946.739.
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The technology and equipment for diesel engines steel fuel pipes cold rolling and coil drawing production on a self-aligning mandrel are considered. We presented current production line scheme for the pipes production, which includes pipe-rolling drum mills, radial forging machines, thermal furnaces with a protective atmosphere, finishing lines for unwinding coils and straightening pipes, a system of conveyors and stores for transferring coils from one unit to another. A list of articles and patents containing basic information on this topic is attached.
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Balic, J., and M. Nastran. "An on-line predictive system for steel wire straightening using genetic programming." Engineering Applications of Artificial Intelligence 15, no. 6 (December 2002): 559–65. http://dx.doi.org/10.1016/s0952-1976(03)00021-6.
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Subrahmanyam, Mslb, V. Vijaya Kumar, and B. Eswara Reddy. "A novel method for segmenting and straightening of text lines in handwritten Telugu documents based on smearing and regression approach." International Journal of Engineering & Technology 7, no. 3 (August 22, 2018): 1846. http://dx.doi.org/10.14419/ijet.v7i3.13286.
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In handwritten document images, segmenting text lines is a very challenging task due to various reasons like variability in intra baseline skew and inter line distance between text lines. So far, no work is reported in the literature for the straightening of handwritten Telugu languages. Telugu is one of the most popular languages of India that is spoken by more than 80 million people especially in South India. Telugu characters are mostly compound characters and that is way the straightening task of Telugu document is more challenging tasks than European languages. This paper introduces a novel approach for segmenting and straightening text lines of handwritten Telugu documents based on smearing and regression approach (SRA). This method initially performs preprocessing and estimates parameters by dividing into connected components of Telugu script. A horizontal and vertical run length-smearing algorithm is used in this paper to shape text lines. To identify text lines more precisely cubic polynomial regression is used between vertical midpoints of two blocks of compound handwritten Telugu characters. A simple logic is derived on this to achieve final process. We tested the proposed algorithm with three different kind of 1000 handwritten documents. The performance of proposed method is evaluated by using matchScore, detection rate, recognition accuracy and F-measure. The experimental results indicates the efficiency of the proposed method over the existing methods.
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Katoh, T., and E. Urata. "Measurement and Control of a Straightening Process for Seamless Pipes." Journal of Engineering for Industry 115, no. 3 (August 1, 1993): 347–51. http://dx.doi.org/10.1115/1.2901671.
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This paper deals with an automatic curing process for out-of-straightness of terminal ends of seamless pipes. The developed curing process is composed of a measuring stage and a controlling stage. In the measuring stage, the out-of-straightness pattern of each pipe is measured automatically, then reference pressure points and press strokes are determined to minimize the sum of squares of deflection angles. In the controlling stage, elastic springback of the pipe is predicted by an observer using the calculated press stroke, on-line measured values of reactive force, and deflection of the pipe. Through a series of experiments, the validity of the proposed process was verified.
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Bosco, Crescentino, and Francesco Tondolo. "Bond Performance in Machined Reinforcing Bar for Reinforced Concrete." Applied Mechanics and Materials 166-169 (May 2012): 828–31. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.828.
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Bond between steel and concrete is surely one of the most important aspects in reinforced concrete (r.c.) structures. The structural behavior in general and the formation of the resistant mechanisms in particular, for r.c. structures depends on bond. Normally bond performance has always been related to the relative rib area; in the recent years, a continuous discussion on code specifications regarding the lowering of the limits for the relative rib area (bond index) is under way. The previous values were based on a wide experimental campaign. In general the latter should guarantee a good level of bond in all the common situations. Moreover building industry increased the use of rebar straightening by means of machines used to straighten and shape rebar in coils for use on construction sites. The straightening produces a damage on the ribs that modifies their geometrical properties, essentially due to the action of the rolling line in which a permanent deformation is induced. In the present work, the experimental results of 60 pull-out tests, carried out according with the RILEM testing method, on ribbed reinforcing bars with different reduced rib profile systematically reproducing the straightening process of coil-reinforcing bar produced are shown. Three different diameters are considered: 8, 12 and 16 mm. The behavior in terms of bond strength response is also compared to the Code provisions and then discussed.
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van Rossum, M., C. L. A. Delicaat, R. Mostert, J. Vermeij, and E. J. G. Spelbos. "On-line bulging and shear measurements near the straightening point in a continuous caster." Revue de Métallurgie 96, no. 6 (June 1999): 729–36. http://dx.doi.org/10.1051/metal/199996060729.
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Park, Jun-Hyoung, and Jae-Woong Kim. "A Study on the Optimum Line Heating Condition for Straightening a Thin Plate Welded Structure." Journal of the Korean Welding and Joining Society 29, no. 2 (April 30, 2011): 40–45. http://dx.doi.org/10.5781/kwjs.2011.29.2.040.
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Kovačič, Miha, Goran Đukić, Brigita Gajšek, and Klemen Stopar. "CAD Based Electric Transporter Path Planning and Production Storage Optimization Using Genetic Algorithm – Industrial Case Study." Tehnički glasnik 14, no. 2 (June 11, 2020): 174–79. http://dx.doi.org/10.31803/tg-20200523200341.
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Štore Steel Ltd. is one of the largest flat spring steel producers in Europe. There are two production lines after rolling – one for flat bars and the other for round bars. The flat bars production generally consists of visual examination, straightening and cutting operation. In addition, heat treatment or magnetic particle testing could be conducted. On the other hand, the round bars production consists generally of straightening, automatic control line control, chamfering and cutting. In addition, heat treatment is possible. For manipulation of the material in the rolling plant, the electric transporter and several cassettes are used. In the paper path planning and production storage optimization (i.e. storage spaces for cassettes) were conducted using genetic algorithm. The production storage is actually the space between main transport passage and individual operations. In the research the universal system using CAD geometry is presented where AutoCAD environment and in-house developed AutoLISP system were used. The production storage – storage spaces for cassettes (location and orientation) with corresponding electric transporter trajectories are represented as CAD objects and thus form individual solution/organism. The organisms undergo simulated evolution. The results of the evolution are compared with actual production storage in the steel plant.
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Elmajri, Khalifa. "Do We have an Aimer to put the Tibial and Femoral Tunnels in the Same Line to reduce Mechanical Strain in Reconstructed Anterior Cruciate Ligament?" International Journal of Recent Surgical and Medical Sciences 03, no. 02 (December 2017): 130–31. http://dx.doi.org/10.5005/jp-journals-10053-0059.
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AbstractThe strain between the ACL graft tissue and the osteochondral tissue at the tunnel entrances would lead to postoperative deviation of the femoral and/or tibial insertion of the ACL graft. Postoperative changes of the 3D orientation of the ACL graft affect its physiometry leading to failure of graft tension. A conception of an aimer is suggested to insure straightening of the intraosseous (tibial and femoral) and intra-articular parts of the graft at the tunnel entry point to overcome the postoperative angulation of intraosseous and intra-articular graft parts
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Chen, Xue, Pan Xue, Yuanyuan Shi, and Si Chen. "The Role of Digital X-Ray in Curative Effect and Nursing Evaluation of Cervical Spondylotic Radiculopathy." Journal of Healthcare Engineering 2021 (August 16, 2021): 1–6. http://dx.doi.org/10.1155/2021/5666136.
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The present study attempted to analyze the features of atlanto-occipital radiograph in patients with cervical spondylotic radiculopathy or vertebral artery type. In order to reduce the interference of human factors and the measurement error as much as possible, this experiment adopts the blind design and analyzes the digital format X-ray films by using the computer software ImageJ. Because the tangent line between the outer plates of the anterior and posterior margin of the foramen magnum was not accurately located on the X-ray film, the angle formed by the line between the saddle dorsal slope and the center point of the anterior and posterior nodule with a clear display was selected as the measurement method of the angle between the atlanto-occipital joints. The results showed that the lateral cervical curvature of the VCS group was 0.43 ± 0.51, and the lateral cervical curvature of the CSR group was 0.46 ± 0.49, both of which were significantly lower than the normal value (1.2 ± 0.5 cm). Patients in both groups had the characteristic of cervical curvature straightening. The changes of cervical curvature in overflexion and overextension positions can indirectly reflect the state of cervical motion. The anterior flexion neck curve of the VCS group was less than that of the CSR group ( P < 0.05 ). Compared with the CSR group, VCS showed limited cervical anterior flexion movement. In this study, X-ray films of both CSR and VCS showed occipitocervical flexion and extension disorders, cervical curvature straightening, and lower cervical instability. In VCS, occipitocervical flexion and extension disorders were mainly manifested in atlantoaxial flexion disorders, while in CSR, atlanto-occipitocervical flexion and extension disorders were mainly manifested in atlantoaxial flexion disorders.
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Hector, Ruiz, Osawa Naoki, Murakawa Hidekazu, Murakawa Hidekazu, and Rashed Sherif. "Development of a Practical Straightening Simulation for Welded Structures Using Inherent Strain Method." KnE Engineering 3, no. 1 (February 11, 2018): 332. http://dx.doi.org/10.18502/keg.v3i1.1438.
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Welding is the most widely used assembly method available to industries in the construction of metal structures, ships, and offshore platforms. However, this method always produces a certain amount of distortion that will not only degrade the performance but also increase the building cost of the structure, and it should be straightened. Murakawa [1] developed a thermal elastic plastic based and inherent strain based welding simulation FE code JWRIAN. Coarse shell FE models are usually used in the inherent strain based JWRIAN elastic analyses. This drastically reduces the manpower needed for modeling and computer resources needed for the calculation. However, it is not easy to perform straightening analysis using JWRIAN because gas heating’s inherent strain distributes over a range much smaller than element sizes of the shell model.RUIZ [2] modified JWRIAN’s code so that the inherent strain equivalent nodal forces along the heating line are calculated and applied in the elastic shell analysis. However, a discrepancy between 3-dimensional thermal-elastic-plastic analysis and elastic analysis was observed. This is mainly because of the nature of solid and shell elements. RUIZ [3] proposed a linearized inherent strain and applied it to both 3-d and 2d analysis, getting matching results between solid and shell element models. In this study, as a working example, a thin plate panel with an opening is considered utilizing the developed system at the same time a friendly user interface for staffs and workers on a production site is developed. Keywords: Inherent strain, straightening, finite element method, Gauss-Legendre quadrature
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Peng, Xuanwei. "Stroke systems in Chinese characters: A systemic functional perspective on simplified regular script." Semiotica 2017, no. 218 (September 26, 2017): 1–19. http://dx.doi.org/10.1515/sem-2015-0111.
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AbstractThis article makes a preliminary attempt to account for the stroke systems of Chinese characters in simplified regular script. The framework utilized is the three meta-functions in Systemic Functional Linguistics. The description observes the cases from the perspectives of the experiential, appraisal (aesthetic), and thematic semiosis of strokes and their constitutional segments to figure out the relevant systems: the line system and the point system. This process witnesses comparisons to seek, in brief though, the traces and origins of stroke development along evolution, and hence the straightening of lines and squaring of character formation. This is the first step towards a rank model of Chinese writing, the whole project of which will highlight a way to study other writing systems in the semiotic respect.
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Žukas, Artūras, Jurijus Zaranka, and Kristina Kemzūraitė. "COMPARISONAL ANALYSIS OF MANUEVERING AND BRAKING." Mokslas - Lietuvos ateitis 2, no. 6 (December 31, 2010): 90–93. http://dx.doi.org/10.3846/mla.2010.119.
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This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt). The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.
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Masubuchi, Koichi. "Recent M.I.T. Research on Residual Stresses and Distortion in Welded Structures." Journal of Ship Production 9, no. 03 (August 1, 1993): 137–45. http://dx.doi.org/10.5957/jsp.1993.9.3.137.
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This paper presents a summary of recent efforts by the Welding Research Group at the Department of Ocean Engineering, M.l.T. The major thrust of the efforts has been to develop technologies of reducing residual stresses and distortion through in-process control. Part 1 discusses reduction of longitudinal bending distortion of built-up beams, reduction of radial distortion and residual stresses in girth- welded pipes, reduction of forces acting on tack welds during butt welding, and reduction of residual stresses and distortion in high-strength steel weldments. Part 2 presents a brief summary of other research studies, including the forming of steel plates by line heating with a high-power laser beam, an intelligent system for flame straightening of panel structures, and the development of a knowledge- based system for minimizing out-of-plane distortion of welded structures.
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Conrardy, Chris, and Randy Dull. "Control of Distortion in Thin Ship Panels." Journal of Ship Production 13, no. 02 (May 1, 1997): 83–92. http://dx.doi.org/10.5957/jsp.1997.13.2.83.
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The increased use of thin section (i.e., less than 10-mm (3/8-in.) thick) steel in ship panel construction has aggravated distortion problems, adding to the costs for fitting and flame straightening. This paper describes the results of a study to evaluate techniques for control of distortion in thin panels used in ship construction. The objective of this project is to identify cost effective techniques for controlling distortion. Buckling is usually the dominant mode of distortion in thin panels, followed by angular distortion. Means of reducing both forms of distortion are discussed. During the design phase relatively small adjustments to the design, such as changing plate thickness or stiffener spacing, can significantly reduce distortion. Improving manufacturing techniques, including reducing weld size, implementing intermittent welding, and restraining the panel during welding, can also make a major impact on reducing distortion. New techniques such as egg-crate construction, laser welding, thermal tensioning, back-side line heating, back-bending, and weld quenching also show promise.
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Eagar, R. M. C. "The shape of the Upper Carboniferous non-marine bivalve Anthraconaia in relation to the organic carbon content of the host sediment." Transactions of the Royal Society of Edinburgh: Earth Sciences 78, no. 3 (1987): 177–95. http://dx.doi.org/10.1017/s0263593300011093.
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ABSTRACTAnthraconaia lived on clay grade sediments. In highly variable life assemblages of the A.prolifera group of the E German Wettin Shales (Stephanian C) organic carbon percentage of the host sediment correlates with wu/m and A/L ratios of the shell (where wu is the maximum width ventral to the line of maximum growth, m, L the maximum length measured parallel to the line of the hinge, and A the length anterior to the umbo). Decrease in the organic carbon of the sediment is associated with decrease in umbonal development, elongation of the shell along the m axis, and straightening and reflection of the ventral margin; the latter becomes subparallel to the dorsum or to the m axis with a concomitant decrease in size. These results confirm and amplify earlier work on Anthraconaia in the Appalachian coalfields. The same morphological trends in relation to organic carbon characterise the Anthraconaia modiolaris group of Britain, both within a single succession in upper Westphalian A sediments in Yorkshire, and also in three shell bands of Lower Westphalian B age in S Wales, Yorkshire and central Scotland. In the last named, above the Musselband Coal, statistical formulae (of Leitch 1940) for the species A.salteri are shown to define neither the type assemblage nor its stratigraphical position. The shell-shape/organic carbon relationship has been broadly confirmed on other horizons of lower Westphalian B age in the Scottish and Pennine coalfields. Far from embarrassing the stratigrapher, the relationship, which reflects ultimately trophic level of deltaic palaeoenvironments, contributes to our understanding of non-marine bivalve faunas, especially of the apparent regional distribution of ‘species’ of Anthraconaia.
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Kuo, H. C., and L. J. Wu. "Prediction of Deformation to Thin Ship Panels for Different Heat Sources." Journal of Ship Production 17, no. 02 (May 1, 2001): 52–61. http://dx.doi.org/10.5957/jsp.2001.17.2.52.
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The increasing use of thin steel plates in manufacturing and the shipbuilding industry has given rise to several issues: massive deformation problems, the need for many skilled workers, and the expense of costs for straightening in on-line processes. This study explains the results of experiments and predicts techniques for the control of deformation in thin panels. The objective of this paper is to explain the use of the G(1,1) Grey method to predict deformation. Bending and buckling are usually the dominant modes of deformation in heat working. It follows angular deformation. De- formation due to different heat sources is discussed. In this paper, laser and torch are used in different constraints, for example, free-free beam and cantilever beam. Many important factors include tiny adjustments during the heat forming process, such as changing the moment speed, intensity of input heating, plate thickness and heating path, to improve manufacture techniques and to predict deformation by data series. For the prediction of deformation, a method to estimate input heating of laser and torch is introduced. The proposed prediction method can be used during the forming process simply and efficiently.
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POON, SHEUNG-HUNG. "ON UNFOLDING LATTICE POLYGONS/TREES AND DIAMETER-4 TREES." International Journal of Computational Geometry & Applications 19, no. 03 (June 2009): 289–321. http://dx.doi.org/10.1142/s0218195909002964.
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We consider the problems of straightening polygonal trees and convexifying polygons by continuous motions such that rigid edges can rotate around vertex joints and no edge crossings are allowed. A tree can be straightened if all its edges can be aligned along a common straight line such that each edge points "away" from a designated leaf node. A polygon can be convexified if it can be reconfigured to a convex polygon. A lattice tree (resp. polygon) is a tree (resp. polygon) containing only edges from a square or cubic lattice. We first show that a 2D lattice chain or a 3D lattice tree can be straightened efficiently in O(n) moves and time, where n is the number of tree edges. We then show that a 2D lattice tree can be straightened efficiently in O(n2) moves and time. Furthermore, we prove that a 2D lattice polygon or a 3D lattice polygon with simple shadow can be convexified efficiently in O(n) moves and in O(n log n) time. Finally, we show that two special classes of diameter-4 trees in two dimensions can always be straightened.
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Nishikawa, Kiisa C., Jenna A. Monroy, Theodore E. Uyeno, Sang Hoon Yeo, Dinesh K. Pai, and Stan L. Lindstedt. "Is titin a ‘winding filament’? A new twist on muscle contraction." Proceedings of the Royal Society B: Biological Sciences 279, no. 1730 (September 7, 2011): 981–90. http://dx.doi.org/10.1098/rspb.2011.1304.
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Recent studies have demonstrated a role for the elastic protein titin in active muscle, but the mechanisms by which titin plays this role remain to be elucidated. In active muscle, Ca 2+ -binding has been shown to increase titin stiffness, but the observed increase is too small to explain the increased stiffness of parallel elastic elements upon muscle activation. We propose a ‘winding filament’ mechanism for titin's role in active muscle. First, we hypothesize that Ca 2+ -dependent binding of titin's N2A region to thin filaments increases titin stiffness by preventing low-force straightening of proximal immunoglobulin domains that occurs during passive stretch. This mechanism explains the difference in length dependence of force between skeletal myofibrils and cardiac myocytes. Second, we hypothesize that cross-bridges serve not only as motors that pull thin filaments towards the M-line, but also as rotors that wind titin on the thin filaments, storing elastic potential energy in PEVK during force development and active stretch. Energy stored during force development can be recovered during active shortening. The winding filament hypothesis accounts for force enhancement during stretch and force depression during shortening, and provides testable predictions that will encourage new directions for research on mechanisms of muscle contraction.
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Kim, Jung-Taek, Jun Han, Sumin Lim, Quan Hu Shen, and Ye Yeon Won. "Kinematically Aligned TKA Aligns the Ankle Joint Line Closer to Those of the Native Ankle than Mechanically Aligned TKA in Bipedal Stance." Journal of Knee Surgery 32, no. 10 (August 21, 2019): 1033–38. http://dx.doi.org/10.1055/s-0039-1694796.
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AbstractMechanically aligned total knee arthroplasty (MATKA) aims to make alignment of the hip, knee, and ankle straight unexceptionally. However, emerging evidence suggests that unexceptional straightening the mechanical axis of the lower limb may lead to clinical and radiological problems of the ankle joint. By contrast, kinematically aligned total knee arthroplasty (KATKA) strives to restore the articular surface of the prearthritic knee. In this study, we examined results from KATKA and MATKA to determine which surgery restores the ankle joint orientation closer to the native ankle joint in bipedal stance and hypothesized that KATKA, rather than MATKA, would be more effective. Data from long-leg standing radiographs of 60 healthy adults (control group, n = 120 knees), patients who underwent MATKA (n = 90 knees), and patients who underwent KATKA (n = 90 knees) were retrospectively reviewed. The hip–knee–ankle angle, orientation of the tibial plafond and the talar dome relative to the ground (G-plafond and G-talus, respectively), and orientation of the plafond relative to the mechanical axis of the limb (M-plafond and M-talus, respectively) were measured and analyzed for comparison. Results show that bipedal stance alignment in patients who underwent KATKA (G-plafond: −0.65 ± 3.03 and G-talus: −1.72 ± 4.02) were not significantly different to native ankle joint alignment indicated by the control group. Compared with the native ankle joint measured in the control group (G-plafond: −0.76 ± 2.69 and G-talus: −1.30 ± 3.25), the tibial plafond and talar dome significantly tilted laterally relative to the ground in ankle joints after MATKA (G-plafond: −2.32 ± 3.30 and G-talus: −2.97 ± 3.98, p = 0.001 and p = 0.004, respectively). Thus, postoperative ankle joint line orientation after KATKA was horizontal to the floor and closer to that of native ankle joints than those after MATKA. The level of evidence is Level III.
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Gulino, G., F. Sasso, R. Falabella, M. Racioppi, E. Sacco, A. D'Onofrio, and P. F. Bassi. "Peyronie's Disease: State of the Art and Future Perspectives." Urologia Journal 74, no. 3 (July 2007): 139–47. http://dx.doi.org/10.1177/039156030707400303.
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Peyronie's disease (PD) is characterized by the onset of a fibrous plaque within the tunica albuginea of the penile corpora cavernosa, resulting in pain and bending during the erection, which can make the intercourse difficult or impossible. Evidence from literature supports the autoimmune etiology of PD, and suggests genetic and familiar conditions, penile traumatisms and history of genital tract diseases as risk factors, even though no definitive conclusions arise about the pathogenesis of the disease. Few randomized trials demonstrated that medical therapies, such as Vitamin E, Colchicine, Potassium amminobenzoate, Tamoxifen and injection therapy with Verapamil are effective in stabilizing the acute phase of the disease. Extracorporeal shock wave therapy (ESWT) and ionophoresis cannot be considered as first line or gold standard therapies. Satisfactory results have been published about Nesbit operation in large number of cases with low-stage disease, whereas plication procedures have shown significant rates of relapse. High incidence of long-term penile retraction have been reported in high-stage disease treated with plaque incision and simple graft insertion. Malleable, soft or inflatable prostheses combined with graft implant have given the best results in terms of penile straightening and lengthening and patients’ satisfaction. In conclusion, the PD etiopathogenesis hasn't been clearly understood-yet, no medical therapy is fully effective; surgery remains therefore the gold standard in case of severe deformity and/or erectile dysfunction.
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Chavoshi, Seyed Ehsan, and Seyed Ebrahim Moussavi Torshizi. "Increasing bending angle in thick-walled pipes with wide heating." Mechanics & Industry 20, no. 6 (2019): 616. http://dx.doi.org/10.1051/meca/2019053.
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The spot heating of a metal part leads to many small deformations. The applications of this method are straightening the bridge parts, turbo-machinery shafts, and so forth. The movement of the heat source on a given path (line heating) leads to an increase in the deformation and the possibility of creating complex bends. However, it is complicated to predict and control the path and velocity of the heat source as well as determining the heat intensity. In the pipes, this method requires simultaneous control over the two torches on both sides of the pipe. The present study aims at investigating the mechanism of deformation and increasing the bending angle in thick pipes by means of a simple heating method. At first, the maximum bending in heating a large circular zone (entitled “wide heating”) is obtained by simulating the process using finite element method and optimizing it applying the genetic aggregation algorithm. Then, a new method for simultaneous heating within two zones is introduced. The interaction between two zones leads to the development of the shortening mechanism in the pipe wall and a significant increase in the bending angle. In this method, there is no need to move the torch where the temperature is controlled more accurately. To evaluate the finite element model, several pipe heating tests are performed with their results being agreed well with the simulation results.
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Lazuardi, Mochamad, Hani Plumeriastuti, and Eka Pramyrtha Hestianah. "PELATIHAN ON-LINE PEMBUATAN PERANGKAT HAND SANITIZER BERBAHAN NON-ALKOHOL PADA PEMUDA BINAAN." Jurnal Layanan Masyarakat (Journal of Public Services) 4, no. 2 (November 29, 2020): 377. http://dx.doi.org/10.20473/jlm.v4i2.2020.377-384.
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Training on non-alcohol based hand sanitizer (HS) was conducted for assisted youth in five districts, namely Gresik, Bojonegoro, Lamongan, Probolinggo and Nganjuk for three days. In the training, competency strengthening was carried out, namely theory and practicum, ending with evaluation of activities. During the implementation of theory and practicum, training materials were provided using social media facilities in the form of WhatsApp and e-mail. Specifically for coordination with participants, a training group was created using social media. The results of the training evaluation turned out that in terms of strengthening the competence of knowledge in making HS and working mechanisms of HS, it was increasing. In terms of straightening the meaning of HS production to be more focused according to the basis of science or good manufacturing practices (GMP). Thus, youth assisted with criteria include youth who are able to pass on knowledge to all young people in their respective districts. Furthermore, the knowledge and skills of the assisted youth in making HS based on non-alcoholic substances will be more agile and targeted. Thus, in reality, the training on making non-alcohol based HS has made the assisted youths become pioneers at the end of the line to pass on their knowledge. The conclusion in the implementation of this training is that the assisted youth are capable and ready to make non-alcohol-based HS as well as being ready to produce for a small scale while showing real work to be transmitted (98%). abstrakTelah dilakukan pelatihan pembuatan hand sanitizer (HS) berbasis non-alkohol terhadap pemuda binaan di lima kabupaten yaitu Gresik, Bojonegoro, Lamongan, Probolinggo dan Nganjuk selama tiga hari. Dalam Pelatihan tersebut dilakukan pemberian penguatan kompetensi yaitu teori dan praktikum diakhiri dengan evaluasi kegiatan. Selama berlangsung pelaksanaan teori dan praktikum, materi pelatihan diberikan menggunakan fasilitas media sosial berupa whatsapp dan e-mail. Khusus koordinasi dengan peserta dilakukan pembuatan grup pelatihan menggunakan media sosial. Hasil evaluasi pelatihan ternyata dari segi penguatan kompetensi pengetahuan pembuatan HS dan mekanisme kerja HS, makin meningkat. Segi pelurusan pengertian produksi HS menjadi makin terarah sesuai basis ilmu pengetahuan atau cara pembuatan obat yang baik (CPOB). Dengan demikian pemuda binaan dengan kritetria termasuk pemuda yang sanggup menularkan ilmu ke seluruh masyarakat muda di kabupaten masing-masing. Lebihlanjut pengetahuan dan ketrampilan pemuda binaan dalam membuat HS berbasis bahan non-alkohol makin cekatan dan terarah. Dengan demikian seacara nyata pelatihan pembuatan HS berbasis non-alkohol telah menjadikan pemuda binaan sebagai pelopor di ujung garis untuk menularkan ilmunya. Kesimpulan dalam pelaksanaan pelatihan ini adalah para pemuda binaan telah sanggup dan siap membuat HS berbasis non-alkohol sekaligus siap berproduksi untuk skala kecil sambil memperlihatkan karya nyata untuk ditularkan (98 %).
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Tabakov, Petr A., and Aleksey P. Tabakov. "Device for checking crankshaft bending and its straightening." Tekhnicheskiy servis mashin, no. 2 (June 10, 2020): 96–101. http://dx.doi.org/10.22314/2618-8287-2020-58-2-96-101.
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Before grinding, the crankshafts are checked for curvature, the allowed runout of the average root neck should be within 0.03-0.05 mm. Straightening is performed on a hydraulic press, installing the crankshaft on prisms in the side root necks, and to check the degree of straightening, one have to move the crankshaft to the grinding machine and fix it on the centers. Such devices have many disadvantages. (Research purpose) The research purpose is in expanding the functionality of the crankshaft straightening device, developing drawings and application of a patent for a device that could check the bending of the crankshaft at the centers, as well as straightening with a fixed reverse bend, which eliminates multiple straightening and increases the life of the shaft and the resource of the internal combustion engine. (Materials and methods) The article proposes upgraded equipment, protected by a patent, to increase the life of the crankshaft, labor productivity by 3-4 times and the accuracity of straightening. (Results and discussion) Authors have made drawings and got patent N191590 from August 14, 2019 for a device for checking the bending of the shaft on the centers and straightening under the press. The article describes the equipment work. (Conclusions) Checking the crankshaft for bending at the centers and straightening with a fixed reverse bend on a single device significantly improves labor productivity and straightening accuracy. The straightening of crankshafts by the proposed method is more than 99 percent without breakdowns.
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Hrechanyi, Oleksii, Tatiana Vasilchenko, Andrii Vlasov, Eduard Huz, and Daria Tsimakhovych. "Influence of technological process parameters on equipment dynamic factor." System technologies 3, no. 134 (April 5, 2021): 3–12. http://dx.doi.org/10.34185/1562-9945-3-134-2021-01.
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Technological equipment of the metallurgical industry operates in difficult conditions in terms of dynamic loads. On the other hand, special requirements are imposed on their mechanisms - they must be reliable in operation and allow easy regulation, and in the event of breakdowns, allow quick replacement or repair of units and parts, and at the same time must meet the conditions for the accuracy of reproduction of the given technological opera-tions.In modern rolling shops, technological operations are carried out according to the continuous and continuous principles of creating new rolling equipment and the operation of complex machines requires the use of achievements in various fields of science and technology. Scissors, straightening machines, coilers, uncoilers, tilters, manipulators, pushers, conveyors are built into the flow technological working lines. And the performance of the technological line as a whole depends on the coordinated work of these mechanisms.The issues of dynamic loads from the point of view of the interaction of the rolling stands of the continuous broadband mill 1680 have been considered rather thoroughly, while the effect of changing the technological modes of rolling on the equipment of the current line, in particular the coiler, is not covered.In order to reduce equipment downtime due to emergency failures associated with an increase in dynamic loads from incorrectly selected technological modes, the task was set to analytically study the effect of a change in the rolling process on the dynamism coefficient using the example of roller coilers of rolling mills.To analyze the forced vibrations arising in the drive of the reel drum of the mill 1680, a two-mass torsion system is considered, to which external moments are applied - the moment of the technological resistance of the working body, reduced to the motor shaft, and the nominal torque of the electric motor.On the basis of the considered calculation scheme, a functional equation of motion was compiled through which the relationship between the change in the parameters of the technological process and the coefficient of dynamism was established.The solution of the functional equation of motion makes it possible to establish the value of the moment of elastic forces as a function of time, which is used in calculating the dynamic coefficient, which in turn characterizes the dynamic loads on the nodes of technological equipment. Its preliminary calculation allows avoiding emergencies associated with equipment failure in case of incorrect selection of the technological process modes.
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Arjes, Heidi A., and Kerwyn Casey Huang. "Straightening up for life in a biofilm." Proceedings of the National Academy of Sciences 117, no. 50 (November 17, 2020): 31573–74. http://dx.doi.org/10.1073/pnas.2021127117.
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Galązka, Piotr, and Janina Kotus. "The straightening theorem for tangent-like maps." Pacific Journal of Mathematics 237, no. 1 (September 1, 2008): 77–85. http://dx.doi.org/10.2140/pjm.2008.237.77.
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Chen, Lin, Zhong Liang Tian, Mi Chao Gao, Wei Zong, Jian Guo Wang, Wen Qing Yang, Ping Yi Wang, Zhang Zhong Wu, Yong Qiang Duan, and Yong Ming Wang. "Researches on Rules of the Longitudinal Residual Stress Distribution in Straightening Deformation Zone of Heavy Rail with Multi-Rollers." Materials Science Forum 575-578 (April 2008): 231–36. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.231.
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The paper simulated and researched the straightening process of heavy rail by finite element software of ANSYS/LS-DYNA. The residual stress of the rail head, rail base, rail loin in the 7th deformation zone meets the real straightening condition in the straightening simulation. The calculation indicates: The residual stress of the rail head, rail base, rail loin in various deformation zones varies significantly like the variation of tensile-compression-tensile. Compared with the on-site rule, the residual stress of rail base decreased155 Mpa, this is in agreement with the values of practice.
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Luzin, Vladimir, C. Rathod, D. Wexler, Paul Boyd, and Manicka Dhanasekar. "Residual Stresses in Rail-Ends from the in-Service Insulated Rail Joints Using Neutron Diffraction." Materials Science Forum 768-769 (September 2013): 741–46. http://dx.doi.org/10.4028/www.scientific.net/msf.768-769.741.
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Insulated rail joints (IRJs) are an integral part of the rail track signaling system and pose significant maintenance and replacement costs due to their low and fluctuating service lives. Failure occurs mainly in rail head region, bolt- holes of fishplates and web-holes of the rails. Propagation of cracks is influenced by the evolution of internal residual stresses in rails during rail manufacturing (hot-rolling, roller-straightening, and head-hardening process), and during service, particularly in heavy rail haul freight systems where loads are high. In this investigation, rail head accumulated residual stresses were analysed using neutron diffraction at the Australian Nuclear Science and Technology Organisation (ANSTO). Two ex-service two head-hardened rail joints damaged under different loading were examined and results were compared with those obtained from an unused rail joint reference sample in order to differentiate the stresses developed during rail manufacturing and stresses accumulated during rail service. Neutron diffraction analyses were carried out on the samples in longitudinal, transverse and vertical directions, and on 5mm thick sliceed samples cut by Electric Discharge Machining (EDM). For the rail joints from the service line, irrespective of loading conditions and in-service times, results revealed similar depth profiles of stress distribution. Evolution of residual stress fields in rails due to service was also accompanied by evidence of larger material flow based on reflected light and scanning electron microscopy studies. Stress evolution in the vicinity of rail ends was characterised by a compressive layer, approximately 5 mm deep, and a tension zone located approximately 5- 15mm below the surfaces. A significant variation of d0 with depth near the top surface was detected and was attributed to decarburization in the top layer induced by cold work. Stress distributions observed in longitudinal slices of the two different deformed rail samples were found to be similar. For the undeformed rail, the stress distributions obtained could be attributed to variations associated with thermo-mechanical history of the rail.
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George, Neethu Mary, and Amruthavalli Potlapati. "What do we need to know about hair straightening?" International Journal of Research in Dermatology 7, no. 5 (August 23, 2021): 748. http://dx.doi.org/10.18203/issn.2455-4529.intjresdermatol20213356.
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<p class="abstract"><span lang="EN-US">Hair straightening is a popular hair procedure. The first hair straightening products were used for African hair. Various modes of hair straightening methods are currently being used. Temporary methods like blow drying and ironing are used for easy manageability of hair, both by modern men and women. Salon- based hair straighteners were initially permanent relaxers which, with time, evolved to formaldehyde-free hair strengthening procedures like hair Botox which is currently in trend. It improves hair manageability, increases hair strength and reduces frizz without producing much chemical damage to hair and by maintaining their natural waves, thereby producing a more natural look. We performed a thorough literature search on the topic in PubMed, consulted various hair stylists and beauty school professors prior to formulation of this article. The article aims at understanding the basic mechanisms involved in various hair straightening methods which helps us to advice patients on a wholesome care of hair.</span></p>
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Guo, Long, and Xingzhong Zhang. "High-Temperature Creep Behaviour and Positive Effect on Straightening Deformation of Q345c Continuous Casting Slab." High Temperature Materials and Processes 37, no. 3 (March 26, 2018): 253–60. http://dx.doi.org/10.1515/htmp-2016-0190.
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AbstractMechanical and creep properties of Q345c continuous casting slab subjected to uniaxial tensile tests at high temperature were considered in this paper. The minimum creep strain rate and creep rupture life equations whose parameters are calculated by inverse-estimation using the regression analysis were derived based on experimental data. The minimum creep strain rate under constant stress increases with the increase of the temperature from 1000 °C to 1200 °C. A new casting machine curve with the aim of fully using high-temperature creep behaviour is proposed in this paper. The basic arc segment is cancelled in the new curve so that length of the straightening area can be extended and time of creep behaviour can be increased significantly. For the new casting machine curve, the maximum straightening strain rate at the slab surface is less than the minimum creep strain rate. So slab straightening deformation based on the steel creep behaviour at high temperature can be carried out in the process of Q345c steel continuous casting. The effect of creep property at high temperature on slab straightening deformation is positive. It is helpful for the design of new casting machine and improvement of old casting machine.
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Galvis Salazar, Juan Camilo, Heriberto Enrique Maury Ramírez, and Roque Julio Hernández Donado. "Elasto-plastic model to determine the maximum force for shaft straightening process." Ingeniería e Investigación 37, no. 2 (May 1, 2017): 107–10. http://dx.doi.org/10.15446/ing.investig.v37n2.61064.
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This paper shows the development of a mathematical model based on elasto-plastic behavior of materials in order to determine the bending moment and the maximum straightening force required to repair a bent shaft. The importance of this work is because many machines use shafts to transmit power and movement, and these elements can suffer permanent deflections during operation cycles. An appropriate reparation process can increase the life of these elements significantly. Knowing the mechanics for a straightening process is essential for design, processes and maintenance engineers in charge of systems that use these elements (shafts).
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Gur’yanov, G. N., and O. B. Kalugina. "INCREASE OF WIRE STRESS STABILITY DEPENDING ON ANTI-TENSION ACTION WHEN FRICTION COEFFICIENT IS INCONSTANT." Izvestiya. Ferrous Metallurgy 62, no. 4 (June 20, 2019): 315–23. http://dx.doi.org/10.17073/0368-0797-2019-4-315-323.
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The strain parameters instability causes variable axial stress during the drawing process. Contact friction specification varies in the shortest time and depends on many factors: homogeneity physico-mechanical properties of the processed material along the length of the pulled billet, quality of technological lubrication, stability of tension force of the billet at the entrance of deformation center and cooling intensity of the fiber, suction drums, washers, rollers, etc. To estimate the effect of friction coefficient on stability of drawing force (stress), first derivative with respect to friction coefficient in drawing equation is used. The first derivative dependence on drawing coefficient is constructed for different hardening models and deformation parameters. Action of anti-tension was investigated when drawing on stressed state of a circular continuous profile. Studies have been carried out for simulation models of hardening. In the course of study, it was proved that it is possible to estimate instability of stressed state by the first derivative with respect to magnitude, depending on friction coefficient of the equation that determines drawing stress. For different deformation parameters, the first derivative with respect to friction coefficient is calculated for the equation determining axial drawing stress. A decrease in magnitude of the derivative is shown with an increase in anti-tension, which indicates expediency of drawing with antitension to stabilize drawing force and to reduce fatigue wear of dies working surface. Calculations were performed for different values of friction coefficient for drawing under the conditions of presence and absence of drawing cylinder and slope angle of drawing cone to drawing axis, mechanical properties of the billet for drawing, and for various coefficients of its hardening. The stabilizing effect of drawing cylinder of dies on drawing stresses with an increased friction coefficient is shown. Instability of drawing stress from deviation of nominal value of friction coefficient depends on values of other strain parameters. In conditions of drawing cylinder presence and small amount of deformation in drawing path and smaller initial friction coefficient, change in its magnitude has a greater effect on stability of the stressed state. Increase in drawing stress stability positively affects quality of wire, operational stability of units and drawing-line elements, for example, due to decrease in fatigue wear of die working surfaces, drawing drums, bypass and straightening rollers. Drawing with anti-tension and the use of special drawing tools stabilize stress state in deformation zone.
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LOMONACO, LUNA. "Parabolic-like mappings." Ergodic Theory and Dynamical Systems 35, no. 7 (July 3, 2014): 2171–97. http://dx.doi.org/10.1017/etds.2014.27.
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In this paper we introduce the notion of parabolic-like mapping. Such an object is similar to a polynomial-like mapping, but it has a parabolic external class, i.e. an external map with a parabolic fixed point. We define the notion of parabolic-like mapping and we study the dynamical properties of parabolic-like mappings. We prove a straightening theorem for parabolic-like mappings which states that any parabolic-like mapping of degree two is hybrid conjugate to a member of the family $$\begin{eqnarray}\mathit{Per}_{1}(1)=\left\{[P_{A}]\,\bigg|\,P_{A}(z)=z+\frac{1}{z}+A,~A\in \mathbb{C}\right\}\!,\end{eqnarray}$$ a unique such member if the filled Julia set is connected.
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Zaides, S. A., and Kuang Le Khong. "Straightening of low-rigid cylindrical details. Part I. Justification of the type of loading and modes at transverse straightening." Izvestiya. Ferrous Metallurgy 62, no. 7 (August 22, 2019): 517–24. http://dx.doi.org/10.17073/0368-0797-2019-7-517-524.
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For straightening of low-rigid cylindrical details like shaft and axes different types of loadings are considered which form tension different in size and in distribution. As the perspective direction, it is possible to consider correction by a bend at the influence of the distributed loading with the subsequent hardening of a billet by superficial plastic deformation based on a cross cheesing of it by flat plates. Purpose of the work was to define tension of the billet at cross correction for the choice of more effective type of loading and processing rational modes. The mathematical apparatus was used based on laws of the theory of an elastoplastic solid and Ansys Workbench software package. Novelty is the research of effective methods of loading at cross correction of cylindrical details. As a result of analytical calculations, value of the residual tension providing correction of cylindrical details was determined. Residual tension necessary for correction of cylindrical details depends on an initial deflection, material and preparation rate. Tension of cylindrical details was defined depending on a type of the application of cross loadings. Bend tension for correction of a shaft at distributed loading is less, than tension from action of cross force. For correction of a shaft with a diameter of 10 mm, 200 mm long and an initial deflection of 0.5 mm it is necessary to create bend tension equal to about 370 MPa. An effective method of loading at cross correction of cylindrical details is the bend at influence of the distributed loading. The received extreme values of bend coefficients are from 5.3 to 5.5 for all cases of shaft rigidity at correction by cross bend at distributed loading with l/L relation equal to 0.8. The developed mathematical model gives quite reliable values of the residual tension providing correction of cylindrical details. The analytical dependence for determination of the size of general deflections and definition of an effective loading type can be recommended for practical use in production for achievement of precision accuracy of low-rigid details like shaft.
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Lou, Xiaoying, Wei Sun, Fatiesa Sulejmani, Minliang Liu, Edward Chen, and Bradley Leshnower. "3067 Biomechanical analysis of acute versus chronic aortic dissection flaps." Journal of Clinical and Translational Science 3, s1 (March 2019): 102. http://dx.doi.org/10.1017/cts.2019.233.
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OBJECTIVES/SPECIFIC AIMS: Thoracic endovascular aortic repair (TEVAR) is more effective in remodeling the dissected aorta in acute versus chronic type B aortic dissection (TBAD). It has been hypothesized that this is due to differences in dissection flap biomechanical and structural properties but has not been confirmed in explanted human aortic tissue. We aimed to characterize and compare differences in tissue biomechanics and microstructure between acute and chronic dissection flaps that may underlie these findings. METHODS/STUDY POPULATION: Dissection flaps were obtained at time of operative repair for patients presenting for open aortic replacement to treat acute type A (ACUTE, n=7) or chronic type B (CHRONIC, n=7) aortic dissection. Given that the current treatment modality for acute complicated TBAD is TEVAR, it was not feasible to acquire acute TBAD flaps for analysis. Tissues were cryopreserved and subjected to biaxial tensile testing in the circumferential and longitudinal directions. Stiffness was quantified by the tangent modulus (TM) in the low and high linear regions of the compiled equibiaxial response curves for each cohort. Extensibility was defined as the intersection of the fitted line from the high linear region with the x-axis, and the degree of anisotropy (DA) was defined as the mean absolute percentage error of the strains in both directions. Flap architecture and collagen fiber organization were also compared between groups using two-photon microscopy. RESULTS/ANTICIPATED RESULTS: Average age of dissection flaps were 3.4±3.4 days in ACUTE and 1,868.7±1,354.0 days in CHRONIC (p=0.011). There were no differences in age, co-morbidities, maximum aortic diameter, and aortic wall thickness. ACUTE exhibited an anisotropic stress-strain response with increased extensibility longitudinally than circumferentially (0.18 vs. 0.09, p=0.022, DA=0.67) while CHRONIC demonstrated an isotropic response with similar extensibility in either direction (0.11 vs. 0.12, p=0.606, DA=0.26). CHRONIC and ACUTE had comparable stiffness in the circumferential direction (TMlow 439.92 vs. 541.08, p=0.729, and TMhigh 1585.19 kPa vs. 1869.35 kPa, p=0.817). In the longitudinal direction, CHRONIC was significantly stiffer than ACUTE (TMhigh 8347.61 kPa vs. 1201.34 kPa, p=0.049) (FIGURE). Microscopy corroborated these findings with greater collagen fiber organization circumferentially than longitudinally in ACUTE and increasing fibrosis, collagen predominance, and straightening of collagen fibers in CHRONIC. DISCUSSION/SIGNIFICANCE OF IMPACT: Compared to ACUTE, CHRONIC exhibited loss of anisotropy with increased tissue stiffness in the longitudinal direction. Increased dissection flap fibrosis and decreased compliance may explain the worse outcomes for aortic remodeling after TEVAR in chronic TBAD. This study offers biomechanical support for early TEVAR in the acute phase of uncomplicated TBAD.