Статті в журналах: "Beam method"

1

Zhang, Tao, and Xian Lei Cao. "The Design Method Study of Double Reinforcement Beam Section." Key Engineering Materials 474-476 (April 2011): 2311–14. http://dx.doi.org/10.4028/www.scientific.net/kem.474-476.2311.

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To simplify the reinforcement design process of double reinforcement beam section, the concept and application of double reinforcement bean section were introduced, and the appropriate application conditions of reinforced beam in practical engineering and the structural design requirements of beams with double reinforcement section designing were analyzed. The results show that the design value of the negative moment, the beam section size and strength grade of concrete shall meet his requirements of the structural design, then the relational expression is derived, applying this formula to judge whether they meet the preliminary requirements before the calculation of beam reinforcement. Compared with the engineering example shows that the design equations is more simple and accurate, but is the upper limit, and the results can provide a reference for the engineering design and related research.

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2

Karvekar, Arvind Vishnu. "An Experimental Study on Rehabilitation of RC Beam by Stitching Method." International Journal for Research in Applied Science and Engineering Technology 9, no. 8 (August 31, 2021): 2955–60. http://dx.doi.org/10.22214/ijraset.2021.37891.

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Abstract: The current work presents an experimental study on rehabilitation of RC beam by stitching method. For the study, a total of Twenty-Four RC beams were casted and cured for 28 days. Among the beams casted, three is control beam. Under two point loading, the control beam was tested for ultimate failure load and remaining twenty one beams were loaded for 75% of the ultimate failure load. The damaged beams were then rehabilitated by Stitching method using two different patterns. The rehabilitated beams were tested for ultimate failure load and the results are compared with control beam and the effectiveness of the rehabilitation is determined. From the result it is observed that as the diameter is gone increasing the flexural strength of the beam is gone increasing. As the depth of insertion of the bar inside the beam is gone increasing the flexural strength of the beam is gone increasing. It is concluded from this study that stitching methods is effective to restore the flexure capacity of damaged beams. Keywords: Rehabilitation, Reinforced Concrete Beam, Stitching Method

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3

Yoo, JW, DJ Thompson, and NS Ferguson. "Energy transfer in a beam-framed structure using a modal method and a wave method at mid frequencies." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 1 (October 7, 2016): 79–95. http://dx.doi.org/10.1177/0954406216673396.

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A fully framed system consisting of four beams and a rectangular plate has been investigated in terms of the energy transfer between the beams and the plate when a force is applied to one of the beams. This configuration, which is a mixture of stiff and flexible elements, is a particularly important example in the industrial area, as it is widely used. A modal model based on interface basis functions is used. A wave model, which is an approximate method, has also been developed in which the plate, acting as a wave impedance, is separately attached to each beam. Experimental studies have been carried out for validation. The investigation with respect to power flow and energy shows the validity of both models in the mid-frequency region. The results show that most energy is dissipated by the flexible plate. The physical phenomena and limitations of the wave method for this particular structural configuration are discussed. Even though it is an approximate method, the wave approach can describe the dynamic characteristics of the excited beam and the plate in terms of the ratios of power and energy of each component. The comparison of the two methods shows that the plate rather than the beams plays a crucial role in transferring the energy from the excited beam to the parallel opposite beam in the beam-framed structure when these two beams have identical properties, whereas the energy transfer is reduced when the beams have dissimilar properties.

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4

Hieu, Nguyen Tran. "Simplified design method and parametric study of composite cellular beam." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 12, no. 3 (April 30, 2018): 34–43. http://dx.doi.org/10.31814/stce.nuce2018-12(3)-04.

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Nowadays, with the development of cutting and welding technologies, steel beams with regular circular openings, called cellular beams, have been widely used for construction. The cellular beams could be designed either as steel beam or composite beam when headed shear connectors connect concrete slab to top flange of steel beam. This paper presents a procedure to design cellular composite beams according to EN 1994-1-1. In addition, a parametric study is carried out to evaluate the influence of circular opening geometry to ultimate load and failure mode of a series of cellular composite beams. As a result, an optimal dimension of cellular beam is proposed. Article history: Received 28 February 2018, Revised 22 March 2018, Accepted 27 April 2018

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5

Pinarbasi, Seval. "Stability Analysis of Nonuniform Rectangular Beams Using Homotopy Perturbation Method." Mathematical Problems in Engineering 2012 (2012): 1–18. http://dx.doi.org/10.1155/2012/197483.

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The design of slender beams, that is, beams with large laterally unsupported lengths, is commonly controlled by stability limit states. Beam buckling, also called “lateral torsional buckling,” is different from column buckling in that a beam not only displaces laterally but also twists about its axis during buckling. The coupling between twist and lateral displacement makes stability analysis of beams more complex than that of columns. For this reason, most of the analytical studies in the literature on beam stability are concentrated on simple cases: uniform beams with ideal boundary conditions and simple loadings. This paper shows that complex beam stability problems, such as lateral torsional buckling of rectangular beams with variable cross-sections, can successfully be solved using homotopy perturbation method (HPM).

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6

Bogardi, Janos J., Ashim Das Gupta, and Huan‐Zheng Jiang. "Search beam method." International Journal of Water Resources Development 7, no. 4 (December 1991): 247–58. http://dx.doi.org/10.1080/07900629108722520.

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7

Adachi, Ahoro, Takahisa Kobayashi, Kenneth S. Gage, David A. Carter, Leslie M. Hartten, Wallace L. Clark, and Masato Fukuda. "Evaluation of Three-Beam and Four-Beam Profiler Wind Measurement Techniques Using a Five-Beam Wind Profiler and Collocated Meteorological Tower." Journal of Atmospheric and Oceanic Technology 22, no. 8 (August 1, 2005): 1167–80. http://dx.doi.org/10.1175/jtech1777.1.

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Abstract In this paper a five-beam wind profiler and a collocated meteorological tower are used to estimate the accuracy of four-beam and three-beam wind profiler techniques in measuring horizontal components of the wind. In the traditional three-beam technique, the horizontal components of wind are derived from two orthogonal oblique beams and the vertical beam. In the less used four-beam method, the horizontal winds are found from the radial velocities measured with two orthogonal sets of opposing coplanar beams. In this paper the observations derived from the two wind profiler techniques are compared with the tower measurements using data averaged over 30 min. Results show that, while the winds measured using both methods are in overall agreement with the tower measurements, some of the horizontal components of the three-beam-derived winds are clearly spurious when compared with the tower-measured winds or the winds derived from the four oblique beams. These outliers are partially responsible for a larger 30-min, three-beam standard deviation of the profiler/tower wind speed differences (2.2 m s−1), as opposed to that from the four-beam method (1.2 m s−1). It was also found that many of these outliers were associated with periods of transition between clear air and rain, suggesting that the three-beam technique is more sensitive to small-scale variability in the vertical Doppler velocity because of its reliance on the point measurement from the vertical beam, while the four-beam method is surprisingly robust. Even after the removal of the rain data, the standard deviation of the wind speed error from the three-beam method (1.5 m s−1) is still much larger than that from the four-beam method. Taken together, these results suggest that the spatial variability of the vertical airflow in nonrainy periods or hydrometeor fall velocities in rainy periods makes the vertical beam velocities significantly less representative over the area across the three beams, and decreases the precision of the three-beam method. It is concluded that profilers utilizing the four-beam wind profiler technique have better reliability than wind profilers that rely on the three-beam wind profiler technique.

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8

Hill, N. Ross. "Gaussian beam migration." GEOPHYSICS 55, no. 11 (November 1990): 1416–28. http://dx.doi.org/10.1190/1.1442788.

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Just as synthetic seismic data can be created by expressing the wave field radiating from a seismic source as a set of Gaussian beams, recorded data can be downward continued by expressing the recorded wave field as a set of Gaussian beams emerging at the earth’s surface. In both cases, the Gaussian beam description of the seismic‐wave propagation can be advantageous when there are lateral variations in the seismic velocities. Gaussian‐beam downward continuation enables wave‐equation calculation of seismic propagation, while it retains the interpretive raypath description of this propagation. This paper describes a zero‐offset depth migration method that employs Gaussian beam downward continuation of the recorded wave field. The Gaussian‐beam migration method has advantages for imaging complex structures. Like finite‐difference migration, it is especially compatible with lateral variations in velocity, but Gaussian beam migration can image steeply dipping reflectors and will not produce unwanted reflections from structure in the velocity model. Unlike other raypath methods, Gaussian beam migration has guaranteed regular behavior at caustics and shadows. In addition, the method determines the beam spacing that ensures efficient, accurate calculations. The images produced by Gaussian beam migration are usually stable with respect to changes in beam parameters.

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9

Lou, Menglin, Qiuhua Duan, and Genda Chen. "Modal Perturbation Method for the Dynamic Characteristics of Timoshenko Beams." Shock and Vibration 12, no. 6 (2005): 425–34. http://dx.doi.org/10.1155/2005/824616.

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Timoshenko beams have been widely used in structural and mechanical systems. Under dynamic loading, the analytical solution of a Timoshenko beam is often difficult to obtain due to the complexity involved in the equation of motion. In this paper, a modal perturbation method is introduced to approximately determine the dynamic characteristics of a Timoshenko beam. In this approach, the differential equation of motion describing the dynamic behavior of the Timoshenko beam can be transformed into a set of nonlinear algebraic equations. Therefore, the solution process can be simplified significantly for the Timoshenko beam with arbitrary boundaries. Several examples are given to illustrate the application of the proposed method. Numerical results have shown that the modal perturbation method is effective in determining the modal characteristics of Timoshenko beams with high accuracy. The effects of shear distortion and moment of inertia on the natural frequencies of Timoshenko beams are discussed in detail.

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10

Al-Ansari, Mohammed Salem, and Muhammad Shekaib Afzal. "Simplified Irregular Beam Analysis and Design." Civil Engineering Journal 5, no. 7 (July 21, 2019): 1577–89. http://dx.doi.org/10.28991/cej-2019-03091354.

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This paper presents simple method to estimate the strength design of reinforced concrete beam sections based on structural safety and reliability. Irregular beam shaped sections are commonly used nowadays in the construction industry. This study reveals the simplified method to analyze and design the different irregular shaped beam sections. In this study, the selected irregular beam shaped sections are divided mainly into three groups, beams with straight edges, beams with sloped edges and circular beams. Each group contains the most commonly used beam shaped sections in that category. Six beams sections (B-1 to B-6) are selected for group-1 whereas five beam sections (B-7 to B-11) and a circular beam section (B-12) are chosen for group 2 and 3 respectively. Flexural beam formulas for three groups of reinforced concrete beams are derived based on section geometry and ACI building code of design. This study also analyzed numerical examples for some of the sections in each group category using the proposed simplified method to determine the strength design of the irregular beams. The results obtained using simplified method for all of the three groups are compared with the finite element software (SAP v2000). The percentage difference of simplified method with the finite element software ranges within 5% to 10%. This makes the simplified method for irregular shaped beam sections quite promising.

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11

Pisani, Marco Andrea, Massimiliano Bocciarelli, and Tommaso D’Antino. "A Method to Calculate the Support Length of Beams Resting on Masonry Walls." Materials 14, no. 23 (November 23, 2021): 7131. http://dx.doi.org/10.3390/ma14237131.

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Rehabilitation, strengthening, and retrofitting of existing masonry buildings represent an important challenge for the construction engineering field. Often, slab strengthening/retrofitting is performed by replacing existing timber and steel beams or by adding new beams to improve the slab load-carrying capacity. The computation of the stresses at the beam–masonry interface (i.e., the contact pressure) is crucial to properly design the beam support length, preventing local failure of masonry and beam. This paper presents a simple analytical procedure to compute the contact pressure at the beam–masonry interface. The analytical procedure is validated by comparison between analytical and corresponding numerical results obtained by finite element modeling. Different types of beam (solid and laminated timber beams and steel beams) were considered, as well as different support conditions (simply resting on the wall considering different support lengths or fully embedded). The results obtained show that the method proposed is simple and reliable, which makes it suitable for professional practice.

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12

Rafi, Muhammad, and Ali Nadjai. "Analytical Method of Temperature Prediction in Reinforced Concrete Beams." Journal of Structural Fire Engineering 5, no. 4 (November 18, 2014): 367–80. http://dx.doi.org/10.1260/2040-2317.5.4.367.

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The determination of temperature profile within a reinforced concrete (RC) beam is essential for carrying out structural analysis at elevated temperatures. The temperatures are usually estimated using sophisticated numerical techniques which require computational support. Since the determination of rebar temperature in RC beams is more important than the concrete temperature a reliable analytical method of temperature prediction can become a helpful tool in simple beam analysis problems which are employed for determining residual strength in fire. This paper presents the details of development of an empirical equation for the prediction of temperature of rebar in RC beams. The equation is also capable of predicting concrete temperatures at different locations within the beam. The predictions made by the equation were compared with the temperatures determined from experimental beam testing and finite element (FE) analysis. A good correlation of the predicted temperatures was found for the entire time-temperature history with both the observed data and the estimated temperatures by FE models.

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13

Li, Yeou Fong, and Shu Ting Kan. "The Mechanical Behavior of the Hybrid FRP Beam." Advanced Materials Research 365 (October 2011): 119–24. http://dx.doi.org/10.4028/www.scientific.net/amr.365.119.

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This paper presents the mechanical behaviors of hybrid fiber reinforced plastic (HFRP) composite beams. There are two methods were proposed to increase the stiffness of pultruded glass fiber reinforced plastic (GFRP) beam and change the failure mode. The first method is to infill the epoxy mortar into the GFRP beam. The second method is hand layout the GFRP beam by using carbon fiber with different direction fibers to increase the stiffness of the GFRP beam. Three-point bending test was conducted to obtain the force-displacement relationship, stiffness, failure strength and failure mode of the GFRP beams. The test results show that the stiffness of GFRP beam filled with epoxy mortar is twice larger than GFRP beam.

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14

Sharma, Prerana. "Cross Focusing of two Coaxial Gaussian Beams with Relativistic and Ponderomotive Nonlinearity." Zeitschrift für Naturforschung A 67, no. 1-2 (February 1, 2012): 10–14. http://dx.doi.org/10.5560/zna.2011-0064.

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This paper presents the cross focusing of two high power lasers by taking off-axial contributions of the laser beams in a collisionless plasma. Due to relativistic and ponderomotive nonlinearities the two laser beams affect the dynamics of each other and cross focusing takes place. The expressions for the laser beam intensities by using the eikonal method are derived. The contributions of the r2 and r4 terms are incorporated. By expanding the eikonal and the other relevant quantities up to the fourth power of r, the solution of the pump laser beam is obtained within the extended paraxial ray approximation. Filamentary structures of the laser beams are observed due to the relativistic and the ponderomotive nonlinearity. The focusing of the laser beams is shown to become fast in the extended paraxial region. Using the laser beam and the plasma parameters, appropriate for beat wave processes, the filaments of the laser beams are studied and the relevance of these results to beat wave processes is pointed out.

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15

Tolhurst, Thomas, Mauricio Barbi, and Tim Tokaryk. "Effective beam method for element concentrations." Journal of Synchrotron Radiation 22, no. 2 (January 29, 2015): 393–99. http://dx.doi.org/10.1107/s1600577514026575.

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There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s).

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16

Cuk, P. E., M. A. Bradford, and N. S. Trahair. "Inelastic lateral buckling of steel beam–columns." Canadian Journal of Civil Engineering 13, no. 6 (December 1, 1986): 693–99. http://dx.doi.org/10.1139/l86-104.

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A series of investigations of the inelastic lateral buckling behaviour of steel beam–columns is described. These originate from many previous studies of the elastic lateral buckling of beams. It was found that present methods of predicting the effects of moment gradient in elastic beam–columns are unnecessarily conservative, and it was concluded that many practical continuous beam–columns will have significant warping restraints.Fourteen inelastic lateral buckling tests were carried out on 9 continuous steel beam–columns. The results of these tests were compared with predictions made by a new and improved finite element computer method of analyzing inelastic buckling, and very good agreement was found. The analytical method was then used to develop a simple approximation for predicting the inelastic buckling of isolated beam–columns with unequal end moments, and a design method was proposed. Key words: beams, buckling, columns, flexure, residual stresses, steel, structural design, structural engineering, torsion.

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17

Naji, Arash. "Improving the tie force method for progressive collapse design of RC frames." International Journal of Structural Integrity 9, no. 4 (August 13, 2018): 520–31. http://dx.doi.org/10.1108/ijsi-10-2017-0058.

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Purpose The purpose of this paper is to recover the deficiency of existing tie force (TF) methods by considering the decrease in section strength due to cracking and by selecting limit state of collapse according to section properties. Design/methodology/approach A substructure is selected by isolating the connected beams from the entire structure. For interior joints, the TFs in the orthogonal beams are obtained by catenary action. For corner joints, the TFs are assessed by beam action. For edge joints, however, the resistance is gained by greater of the resistance under catenary action for periphery beams and beam action for all the connecting beams in both directions. For catenary action, the TF capacities must satisfy Equation (20). On the other hand, for beam action, the TF must satisfy Equation (16), while R is calculated from Equation (17). In the case where the length of the connecting beams is similar, Equation (19) can be used. Findings Closed form solutions are available for TFs on both beam and catenary stages. Originality/value The proposed formulation makes designing more practical and convenient. However, the proposed formulation had good agreement with experimental results.

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18

Шевченко, Andrey Shevchenko, Шаповалов, and Sergey Shapovalov. "CALCULATION OF COMPOSITE WOOD BEAMS IS BASED ON VARIATIONAL METHOD." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 1 (December 8, 2016): 88–91. http://dx.doi.org/10.12737/23928.

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The relevance of the study is to optimize the calculation in the design of beams of The relevance of the study is to optimize the calculation in the design of beams of wooden buildings with the definition of efforts and deformations of the beam, the elements of the frame and the casing, by applying the variational method V. Z. Vlasov, when a wooden beam is represented as a rod of composite sections.

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19

Liu, J. M., and L. Gomelsky. "Vectorial beam propagation method." Journal of the Optical Society of America A 9, no. 9 (September 1, 1992): 1574. http://dx.doi.org/10.1364/josaa.9.001574.

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20

MANSURIPUR, MASUD, EWAN M. WRIGHT, and MAHMOUD FALLAHI. "The Beam Propagation Method." Optics and Photonics News 11, no. 7 (July 1, 2000): 42. http://dx.doi.org/10.1364/opn.11.7.000042.

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21

Kaczmarski, P., and P. E. Lagasse. "Bidirectional beam propagation method." Electronics Letters 24, no. 11 (May 26, 1988): 675–76. http://dx.doi.org/10.1049/el:19880457.

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22

Jun Wang, Jun Wang, Lihua Huang Lihua Huang, Liying Hou Liying Hou, Guojun He Guojun He, Qiang Song Qiang Song, and Huijie Huang Huijie Huang. "Study of active beam steering system with a simple method." Chinese Optics Letters 12, no. 8 (2014): 081405–81409. http://dx.doi.org/10.3788/col201412.081405.

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23

Alam, Md Ashraful, Ali Sami Abdul Jabbar, Mohd Zamin Jumaat, and Kamal Nasharuddin Mustapha. "Effective Method of Repairing RC Beam Using Externally Bonded Steel Plate." Applied Mechanics and Materials 567 (June 2014): 399–404. http://dx.doi.org/10.4028/www.scientific.net/amm.567.399.

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Repair of reinforced concrete beam with externally bonded steel plate or fibre reinforced polymer (FRP) laminate is becoming both environmentally and economically preferable rather than replacement of deficient beam. The well known advantages of external reinforcement over other methods include; low cost, ease of maintenance and the ability to strengthen part of the structure while it is still in use. The disadvantage of this method, however, is the premature debonding of the externally bonded strips which is brittle and undesired mode of failure. It is also known that debonding of the externally bonded steel plates prevents the reinforced concrete (RC) beam from reaching its full strengthening capacity. The aim of this study was to increase the scientific understanding on the behaviour of damaged reinforced concrete beams strengthened and/or retrofitted for shear using vertical steel plate fixed with adhesive and steel connectors to eliminate or delay debonding failure. Four reinforced concrete beam specimens were prepared to investigate the effects of connectors in preventing or delaying premature debonding of shear strips to restore the capacities of fully damaged beams. Three damaged beams have been repaired and strengthened with steel plates and loaded monotonically up to the maximum load capacities in order to define load–deflection relationship. It is concluded that the repairing of severely shear-damaged RC beams with steel plates by using steel and adhesive connectors can fully restore the original shear capacities of the beams.

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24

Cui, Xin, Yong Jiang, Li Wen Fu, and Jin Feng Wang. "The Research on Cable Force Measurement Based on Degenerated Element with Frequency Method." Applied Mechanics and Materials 405-408 (September 2013): 1709–15. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1709.

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At present, among the methods of cable force measurement, the frequency method is applied extensively for its mature theory and rapid and repeated operation procedure. Based on the theory of frequency method measurement, it generally uses the numerical method with beam element to analysis the parameters of cables under the given conditions. However, the conventional beam element is not able to simulate the bending stiffness in beams section. Therefore, it turns to degenerated beam element to simulate cables and the results agree well with the results based on beam element and formulas calculation, and it provides theoretical basis for the later cable force testing system.

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25

Rozhkov, Konstantin A., Sergey S. Starikov, Stepan V. Varushkin, Dmitry N. Trushnikov, and Irina A. Zubko. "ON IMPROVING THE METHOD OF ELECTRON-BEAM DEPOSITION." Journal of Physics: Conference Series 2077, no. 1 (November 1, 2021): 012017. http://dx.doi.org/10.1088/1742-6596/2077/1/012017.

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Abstract The paper deals with improvement of the electron-beam additive forming of metal products using a vertically fed filler wire in vacuum with two electron beams as a heating source. We compared the importance of the power of the heat source required for fusing the layers with each other and the calculated power of the heat source required to melt the filler wire and the surface of the product. Within the experimental conditions of the multilayer electron beam deposition using side wire feeding, the electron beam power of 2.4 kW was required to ensure fusion without the defect formation between the layers during the deposition of Ti-6Al-4V titanium alloy. At the same time, approximate calculations of the minimum power of the heat source required to melt the filler wire and the surface of the product showed a level of 730 W.

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26

Guo, Shi Wei. "Dual Variables System Analysis for Timoshenko Beam." Applied Mechanics and Materials 423-426 (September 2013): 1473–84. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.1473.

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Regarding the displacements and internal forces of Timoshenko beams as dual variables, Timoshenko beam problems were included into dual variables system. Corresponding to state transfer solution of Hamiltonian dual equation, transfer form solution of dual variables for Timoshenko beams was presented. Based on transfer form solution, element stiffness equation and the shape functions of Timoshenko beams were deduced, boundary integral equation and the fundamental solution function of Timoshenko beams were obtained, which reveal the intrinsic relationships among the finite element method, the boundary element method and dual variables system of Timoshenko beams. Based on the transfer form solution of Timoshenko beams, transfer matrix method for chain structure of Timoshenko beams was proposed. For chain beam structure problems, transfer matrix method is simple, intuitive, and has the advantages of good boundary adaptability and less calculation in solving the node variables of chain structures with recursive solution. The numerical results demonstrate the feasibility and accuracy of transfer matrix method in complex beam structure problems.

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27

Choi, Insub, Dongwon Kim, and Junhee Kim. "Development of Optimal Design Method for Steel Double-Beam Floor System Considering Rotational Constraints." Applied Sciences 11, no. 7 (April 6, 2021): 3266. http://dx.doi.org/10.3390/app11073266.

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Under high gravity loads, steel double-beam floor systems need to be reinforced by beam-end concrete panels to reduce the material quantity since rotational constraints from the concrete panel can decrease the moment demand by inducing a negative moment at the ends of the beams. However, the optimal design process for the material quantity of steel beams requires a time-consuming iterative analysis for the entire floor system while especially keeping in consideration the rotational constraints in composite connections between the concrete panel and steel beams. This study aimed to develop an optimal design method with the LM (Length-Moment) index for the steel double-beam floor system to minimize material quantity without the iterative design process. The LM index is an indicator that can select a minimum cross-section of the steel beams in consideration of the flexural strength by lateral-torsional buckling. To verify the proposed design method, the material quantities between the proposed and code-based design methods were compared at various gravity loads. The proposed design method successfully optimized the material quantity of the steel double-beam floor systems without the iterative analysis by simply choosing the LM index of the steel beams that can minimize objective function while satisfying the safety-related constraint conditions. In particular, under the high gravity loads, the proposed design method was superb at providing a quantity-optimized design option. Thus, the proposed optimal design method can be an alternative for designing the steel double-beam floor system.

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28

Lin, Q., Z. Sun, and J. Corbett. "An adaptive masking method for beam halo measurement by a digital micro mirror device." Journal of Instrumentation 16, no. 11 (November 1, 2021): T11005. http://dx.doi.org/10.1088/1748-0221/16/11/t11005.

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Abstract In high intensity particle beams, irregularities in cathode emission, scattering effects, dark current and space charge forces can lead to a common phenomenon termed beam halo with associated emittance growth, beam loss and overall beam quality degradation. It is of fundamental interest and practical importance to precisely monitor such beam halo, which could offer valuable insights into the experimental strategy for the suppression of this undesired feature [1]. A Digital Micro mirror Device (DMD) is a computer-controlled micro-electrical-mechanical system that contains a compact array of physically independent reflective mirrors. Using a standard DMD, we come up with an adaptive masking method for halo measurement, which demonstrates superior robustness and efficiency comparing to the conventional approaches as confirmed by simulation and experimental results. Our development includes an integrated package of hardware, software and a graphic user interface (GUI) that is robust and portable and can be applied as a beam halo diagnostic for electron guns or radiating charged particle beams in general.

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29

You, Guoqiang. "A Structural Analysis Method for Cable-Beam Composite Structure." Mathematical Problems in Engineering 2020 (June 1, 2020): 1–13. http://dx.doi.org/10.1155/2020/8318064.

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A structural analysis method is proposed in this paper for cable-beam composite structure with a large number of cable elements; it can improve computational efficiency and accuracy. Firstly, we use a structural division method to divide the whole cable-beam structure into inner cablenet system and edge cablenet-beam system. Because inner cablenet is a pure cablenet structure with given shape and topology, balance matrix analysis method is used to help obtain the best pretension distribution of it with the evenness as objective. For edge cablenet-beam system, with obtaining equilibrium forces of inner cablenet’s pretensions as goal, an iterative pretension losses compensation calculation combined with nonlinear finite element method and balance matrix analysis method is used for edge cablenet to adjust its pretension distribution and make the whole cablenet system keep its preset ideal shape under influence of beams’ deformations. Because edge cablenet-beam system has a lot less cable elements than overall structure, its nonlinear finite element calculations are much easier and faster than those for the whole cable-beam composite structure. In order to verify the above method’s validity, it is used for a spaceborne cablenet deployable antenna example, and the computed results indicate that the method is feasible.

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30

Zhang, Tao. "A Method for Design of Oblique Intersection Beams in Roof Structures." Advanced Materials Research 211-212 (February 2011): 827–31. http://dx.doi.org/10.4028/www.scientific.net/amr.211-212.827.

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To facilitate calculation of a reinforced concrete oblique intersection beams in roof structures, the analysis ignores the interaction between moment and torque of node position, assuming the beam ends as hinge supports. Vertical displacement coefficients were found out by unit-load method, the compatibility equation of displacement was set up by the conditions of equal displacement at nodes, which can finally calculate force diagram of beams, and further design beam section. When designing, it is necessary to note reinforcement calculation should be taken into account the change of beam effective cross-section high caused by longitudinal tension reinforcement layer placed. Compared with the engineering example show that the design method is more simple and accurate, the results can provide a reference for the engineering design and related research.

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31

Hill, N. Ross. "Prestack Gaussian‐beam depth migration." GEOPHYSICS 66, no. 4 (July 2001): 1240–50. http://dx.doi.org/10.1190/1.1487071.

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Kirchhoff migration is the most popular method of three‐dimensional prestack depth migration because of its flexibility and efficiency. Its effectiveness can become limited, however, when complex velocity structure causes multipathing of seismic energy. An alternative is Gaussian beam migration, which is an extension of Kirchhoff migration that overcomes many of the problems caused by multipathing. Unlike first‐arrival and most‐energetic‐arrival methods, which retain only one traveltime, this alternative method retains most arrivals by the superposition of Gaussian beams. This paper presents a prestack Gaussian beam migration method that operates on common‐offset gathers. The method is efficient because the computation of beam superposition isolates summations that do not depend on the seismic data and evaluates these integrals by considering their saddle points. Gaussian beam migration of the two‐dimensional Marmousi test data set demonstrates the method’s effectiveness for structural imaging in a case where there is multipathing of seismic energy.

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32

Yang, E. Chuan, Xiang Zhao, and Ying Hui Li. "Free Vibration Analysis for Cracked FGM Beams by Means of a Continuous Beam Model." Shock and Vibration 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/197049.

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Based on Euler-Bernoulli beam theory and a continuous stiffness beam model, the free vibration of rectangular-section beams made of functionally graded materials (FGMs) containing open edge cracks is studied. Assuming the material gradients follow exponential distribution along beam thickness direction, the conversion relation between the vibration governing equations of a FGM beam and that of an isotropic homogenous beam is deduced. A continuous function is used to characterize the bending stiffness of an edge cracked FGM beam. Thus, the cracked FGM beam is treated as an intact beam with continuously varying bending stiffness along its longitudinal direction. The characteristic equations of beams with different boundary conditions are obtained by transfer matrix method. To verify the validity of the proposed method, natural frequencies for intact and cracked FGM beams are calculated and compared with those obtained by three-dimensional finite element method (3D FEM) and available data in the literature. After that, further discussions are carried out to analyze the influences of crack depth, crack location, material property, and slenderness ratio on the natural frequencies of the cracked FGM beams.

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33

Hashempoor, Davood, and Rouhollah Talebitooti. "A Novel Approach to Elasto-Plastic and Plastic Finite Element Analysis of Functionally Graded Beams under Transverse Pressure Loading." Mapta Journal of Mechanical and Industrial Engineering (MJMIE) 1, no. 1 (December 20, 2017): 1–13. http://dx.doi.org/10.33544/mjmie.v1i1.16.

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In this study a new numerical-analytical method for elasto-plastic and plastic modelling and simulating of FG beams is presented. The functionally graded (FG) beam composed of ten layers through the thickness and it is assumed that the mechanical properties of the beam vary through the thickness described by a simple power law distribution in terms of the volume fractions of constituents. The beam is assumed to be under transverse pressure load. In this paper a new method is presented based on linearization of the nonlinear part of the stress-strain curve of the material of the layers of the FG beam and using the elastic relations for bending analysis of beams. Numerical results for functionally graded beam are given and results of this paper for homogeneous beam are compared with other methods and good agreement is obtained between them. In addition, the effects of material properties on the stress field through the thickness of the FG beam are determined and discussed.

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34

Hong, Wan, Yuchen Jiang, Yong Fang, and Xiamin Hu. "Experimental study and theoretical analysis of glulam-concrete composite beams connected with ductile shear connectors." Advances in Structural Engineering 23, no. 6 (December 4, 2019): 1168–78. http://dx.doi.org/10.1177/1369433219891560.

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Ductile shear connectors are often applied in timber-concrete composite beams. The relative interface slip of such kind of composite beams will affect the mechanical performance of the composite beams and result in structural nonlinearity. Gamma method which adopts effective bending stiffness to reflect semi-rigid connection is recommended in Eurocode 5. The effective bending stiffness is irrelevant to external loads and calculation points of the composite beam. However, actual bending stiffness distribution along the beam is variable due to that shear connectors are subjected to different shear force. In order to verify the accuracy of gamma method, four-point bending tests of a total of three glulam-concrete composite beams with lag screw connectors and one pure glulam beam were conducted in this article. The failure mode, bearing capacity, and load–deflection relationship were investigated in the experiment. Meanwhile, push-out tests of composite beams were also conducted for determination of the force–displacement relationship of ductile shear connectors. Then, numerical simulation using beam-truss model was established for investigation on the mechanism of composite beams. Finally, theoretical analysis of composite beams considering the effect of interface slip was also presented. Comparing results from gamma method with the presented method, it is shown that both methods can calculate deflection at serviceability limit state with high precision. However, non-uniform distribution of actual bending stiffness cannot be reflected by gamma method.

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35

Liu, Han Bing, Bai Ying Wang, Peng Zhang, and Yu Bo Jiao. "Research on Bridge Transverse Load Distribution Coefficient of Beam System Theory Based on Finite Difference Method." Advanced Materials Research 694-697 (May 2013): 3195–98. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.3195.

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The calculation methods of transverse load distribution coefficient based on beam system theory include hinge method and rigid connected beam method. The calculation process is complicated and can usually be used through special tables. However, the traditional tables for ten beams can not satisfy the design requirements with the development of transportation. Therefore, a series of simple and practical analytical formula are proposed based on finite difference method. A numerical simulation of simply supported beam bridge is used to verify the effectiveness of the proposed method. The results reveal that the proposed method possesses favorable accuracy.

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36

Peng, Li, and Ying Wang. "Differential Quadrature Method for Vibration Analysis of Prestressed Beams." E3S Web of Conferences 237 (2021): 03029. http://dx.doi.org/10.1051/e3sconf/202123703029.

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This paper investigates natural frequencies of free transverse vibrations of prestressed beams, and the governing equations and natural frequencies of the free vibration in related literatures are discussed and corrected. The differential quadrature methods (DQ) are applied directly to the corrected governing equations to get the the values of natural frequency numerically. Under the simple supported boundary conditions, the natural frequencies of model beam are numerically studied, and the physical parameters of the beam are analyzed respectively. The numerical results show that the natural frequency values increase with the growth of concrete strength and eccentricity of prestressed steels. But with the increase of the span length of beam and values of original prestressing force, the natural frequency values decrease.

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37

Keshmiri, Alireza, Nan Wu, and Quan Wang. "Free Vibration Analysis of a Nonlinearly Tapered Cone Beam by Adomian Decomposition Method." International Journal of Structural Stability and Dynamics 18, no. 07 (July 2018): 1850101. http://dx.doi.org/10.1142/s0219455418501018.

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In this paper, the free vibration of a nonlinearly tapered cone beam is analyzed based on the Euler–Bernoulli hypothesis. The characteristic/eigenvalue equation and mode shape functions of the nonlinearly tapered cone beam are derived by the Adomian decomposition method for the first time. Using a modified mathematical procedure, the natural frequencies and mode shape functions of a general nonuniform beam are analytically derived. Several numerical examples for the vibration of uniform and linearly tapered cantilever beams are presented and compared with previous results to validate the accuracy and fast convergence of the present approach. The natural frequencies and mode shapes of vibration of exponentially and trigonometrically tapered cone beams with different taper ratios are presented. The present approach enables engineers to analytically analyze tapered beams of nonuniform configurations used as various structural components in a mathematically efficient way.

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38

Luo, Qingchun, Yantao Zhou, Yihong Qi, Pu Ye, Francesco de Paulis, and Lie Liu. "Rapid Test Method for Multi-Beam Profile of Phased Array Antennas." Sensors 22, no. 1 (December 22, 2021): 47. http://dx.doi.org/10.3390/s22010047.

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The measurement of the phased array antenna (PAA) is completely different from the traditional antenna, due to its multi beam patterns. Usually, each beam pattern of the PAA needs a separate measurement, which makes the overall time extremely long. Thus, the traditional method can no longer meet the efficiency and cost requirements of new PAA measurement. In this paper, a pattern reconstruction method is proposed which significantly reduce the measurement time of multi-beam PAAs. With the known array element patterns (AEP) and theoretical weighted port excitation of the beams, any beam pattern can be predicted by measuring only a certain beam pattern, due to the element excitation coefficient (including the matching, mutual coupling, and manufacturing factors, etc.) of the specific PAA being calculated. The approach has low reconstruction error in term of beam pointing accuracy, side lobe, and co-polar and cross-polar patterns while being validated for large scanning range. Through theoretical derivation and experiments, the effectiveness of the method is verified, and the testing efficiency of the phased array antenna can be improved by 10 times or even more.

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39

Jamali, Shojaeddin, Tommy H. T. Chan, Ki-Young Koo, Andy Nguyen, and David P. Thambiratnam. "Capacity Estimation of Beam-Like Structures Using Substructural Method." International Journal of Structural Stability and Dynamics 18, no. 12 (November 9, 2018): 1850162. http://dx.doi.org/10.1142/s0219455418501626.

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Evaluating the performance of beam-like structures in terms of their current boundary conditions, stiffness and modal properties can be challenging as the structures behave differently from their designed conditions due to aging. The purpose of the current study is to determine the flexural rigidity of beam-like structures when their support conditions are not fully understood. A novel optimization scheme is proposed for estimation of the flexural stiffness and the capacity of the beam-like structures under moving loads. The proposed method is applied to various profiles of the beams made of different materials with unknown boundary conditions, and the effects of damage, excitation and optimization algorithm are rigorously investigated. The results of the numerical and experimental studies showed that the proposed substructural bending rigidity identification (SBI) method can correctly assess the in-service flexural stiffness, fixity of the boundary condition and the load-carrying capacity. This technique can be considered as a cost-effective method for periodic monitoring, load rating and model updating of the beam-like structures.

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40

Jin, Shi, Hao Wu, and Xu Yang. "Semi-Eulerian and High Order Gaussian Beam Methods for the Schrödinger Equation in the Semiclassical Regime." Communications in Computational Physics 9, no. 3 (March 2011): 668–87. http://dx.doi.org/10.4208/cicp.091009.160310s.

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AbstractA novel Eulerian Gaussian beam method was developed in [8] to compute the Schrödinger equation efficiently in the semiclassical regime. In this paper, we introduce an efficient semi-Eulerian implementation of this method. The new algorithm inherits the essence of the Eulerian Gaussian beam method where the Hessian is computed through the derivatives of the complexified level set functions instead of solving the dynamic ray tracing equation. The difference lies in that, we solve the ray tracing equations to determine the centers of the beams and then compute quantities of interests only around these centers. This yields effectively a local level set implementation, and the beam summation can be carried out on the initial physical space instead of the phase plane. As a consequence, it reduces the computational cost and also avoids the delicate issue of beam summation around the caustics in the Eulerian Gaussian beam method. Moreover, the semi-Eulerian Gaussian beam method can be easily generalized to higher order Gaussian beam methods, which is the topic of the second part of this paper. Several numerical examples are provided to verify the accuracy and efficiency of both the first order and higher order semi-Eulerian methods.

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41

Herring, R. A., and T. Tanji. "CBED+EBI holography of materials structures." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 1086–87. http://dx.doi.org/10.1017/s042482010015126x.

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A new method of holography is presented using the CBED+EBI technique of interferomctry. The CBED+EBI method produces interferograms by using an electron biprism to interfere diffracted beams produced from a convergent beam probe. Holography is made possible by the fact that the beams continue to interfere as they are displaced from each other slightly, Fig. 1. This fact enables an object beam to be taken from one part of a crystal (e.g. a crystal defect) and a reference beam to be taken from another part of the crystal (e.g. the perfect crystal). The interference results in a phase shift around the dissimilar region. As well, for small defects which do not disturb or phase shift one beam (say the main beam) significantly but do so with the diffracted beam, directly overlaying the two beams results in a significant phase shift at the small defect. These methods are very easy to apply although the interpretation of phase shifted regions still requires knowledge of the crystal, its diffraction characteristics and interference effects.

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42

Ropay, V., L. Telipko, and O. Romanyuk. "UNIVERSAL METHOD OF CALCULATION OF MULTISPAN BEAMS." Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) 1, no. 38 (September 8, 2021): 40–47. http://dx.doi.org/10.31319/2519-2884.38.2021.5.

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The supporting structures of machines and mechanisms of metallurgical equipment, which are characterized by large dimensions, in the calculation scheme can be reduced to multispan beams, which are statically indeterminate. Traditionally, the disclosure of their static uncertainty is based on the graphoanalytical method, which is called "Equation of 3 moments". According to this method, the equations of three points are solved by constructing intermediate epure of bending moments, finding their areas and position of the centers of gravity. These procedures lead to an unreasonable increase in time to solve the problem. It is advisable to have an analytical method for detecting static uncertainty of multispan beams, which would be free from graphical constructions and would significantly reduce the time to solve the problem. At the present stage, the calculation of complex spatial structures is carried out using the calculation and software systems "LIRA", "SCAD" and others. However, this in no way limits the need for the application in engineering practice of simple analytical methods, which include a universal method for detecting static indeterminateness of multispan beams. Additional, to the static equations, the equations of displacement are compiled using the universal equation of the bent axis of the beam, and the number of beams can be any large. Different variants of boundary conditions are considered. The results of the considered examples prove the independence of the values of "extra" unknown from the stiffness of the beam. The universal method is quite optimal, as it uses a very simple universal equation of the bent axis of the beam and, with each subsequent additional equation of displacement differs from the previous one only by adding another item with a new load. This approach provides the optimal solution to almost any problem, by revealing the static indeterminateness of multispan beams.

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43

Al Rjoub, Yousef S., and Azhar G. Hamad. "Free Vibration of Axially Loaded Multi-Cracked Beams Using the Transfer Matrix Method." March 24, No 1 (March 2019): 119–38. http://dx.doi.org/10.20855/ijav.2019.24.11274.

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In this paper, an analytical method is developed to study the free vibration of multi-cracked, axially loaded beams with differing boundary conditions, namely, hinged-hinged, clamped-clamped, clamped-hinged, and clamped-free. The cracked beam system is modelled as a number of beam segments connected by massless rotational springs with sectional flexibility. Each segment is assumed to obey the Euler-Bernoulli beam theory. The characteristic equation of the cracked beam with differing boundary conditions, which is a function of the natural frequency, sizes and location of the cracks, and the physical parameters of the beam, as well as the corresponding mode shapes, is derived using a simple transfer matrix method. In this paper, a detailed parametric study is conducted to show the effects of cracks and axial load on vibrational properties of the cracked beam. The results obtained in this study agree well with analytical results available in the literature.

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44

Demir, D. Dönmez, and E. Koca. "Variational Iteration Method for Transverse Vibrations of the Elastic, Tensioned Beam." International Journal of Materials, Mechanics and Manufacturing 5, no. 3 (August 2017): 187–90. http://dx.doi.org/10.18178/ijmmm.2017.5.3.315.

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45

Mizota, M., and S. Fukuda. "Updating of HIMAC beam delivery with broad beam method." Journal of Radiation Research 55, suppl 1 (February 28, 2014): i106. http://dx.doi.org/10.1093/jrr/rrt158.

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46

Ma, Xiao, Shuai Wang, Bo Zhou, and Shifeng Xue. "Study on Electromechanical Behavior of Functionally Graded Piezoelectric Composite Beams." Journal of Mechanics 36, no. 6 (August 6, 2020): 841–48. http://dx.doi.org/10.1017/jmech.2020.44.

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ABSTRACTThis paper investigates the electromechanical behavior of functionally graded piezoelectric composite beams containing axially functionally graded (AFG) beam and piezoelectric actuators subjected to electrical load. The mechanical properties of the AFG beam are assumed to be graded along the axial direction. Employing the electromechanical coupling theory and load simulation method, the expression for the simulation load of the piezoelectric actuators is obtained. Based on Euler-Bernoulli beam theory and the obtained simulation load, the differential governing equation of the piezoelectric composite beams subjected to electrical load is derived. The integration-by-parts approach is utilized to solve the differential governing equation, and the expression for the deflection of the piezoelectric composite beams is obtained. The accuracy of the proposed method is validated by the finite element method. The bending response of the functionally graded piezoelectric composite beams is investigated through the proposed method. In the numerical examples, the effects of electrical load, actuator thickness, AFG beam thickness and AFG beam length on the electromechanical behavior of the functionally graded piezoelectric composite beams are studied.

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47

Cao, MS, W. Xu, Z. Su, W. Ostachowicz, and N. Xia. "Local coordinate systems-based method to analyze high-order modes of n-step Timoshenko beam." Journal of Vibration and Control 23, no. 1 (August 9, 2016): 89–102. http://dx.doi.org/10.1177/1077546315573919.

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High-frequency transverse vibration of stepped beams has attracted increasing attention in various industrial areas. For an n-step Timoshenko beam, the governing differential equations of transverse vibration have been well established in the literature on the basis of assembling classic Timoshenko beam equations for uniform beam segments. However, solving the governing differential equation has not been resolved well to date, manifested by a computational bottleneck: only the first k modes ( k ≤ 12) are solvable for i-step ( i ≥ 0) Timoshenko beams. This bottleneck diminishes the completeness of stepped Timoshenko beam theory. To address this problem, this study first reveals the root cause of the bottleneck in solving the governing differential equations for high-order modes, and then creates a sophisticated method, based on local coordinate systems, that can overcome the bottleneck to accomplish high-order mode shapes of an n-step Timoshenko beam. The proposed method uses a set of local coordinate systems in place of the conventional global coordinate system to characterize the transverse vibration of an n-step Timoshenko beam. With the method, the local coordinate systems can simplify the frequency equation for the vibration of an n-step Timoshenko beam, making it possible to obtain high-order modes of the beam. The accuracy, capacity, and efficiency of the method based on local coordinate systems in acquiring high-order modes are corroborated using the well-known exact dynamic stiffness method underpinned by the Wittrick-Williams algorithm as a reference. Removal of the bottlenecks in solving the governing differential equations for high-order modes contributes usefully to the completeness of stepped Timoshenko beam theory.

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48

Mukherjee, Kingshuk. "Numerical Simulation of Reinforced Concrete beam Under Flexure Using Finite Element Method." International Journal for Research in Applied Science and Engineering Technology 10, no. 12 (January 31, 2022): 409–17. http://dx.doi.org/10.22214/ijraset.2022.39851.

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Abstract: Understanding the response of concrete structural components such as beams, columns, walls during loading is indispensable for the development of safeand efficient structures. The present report deals with the non-linear static analysis of a Reinforced Concrete (RC) beam, having dimensions 4000mmX400mmX 250mm, with 4 nos. of 16mm diameter bar as main reinforcements, 8mm diameter at 200mm c/c as shear reinforcement, with two faces of the beam as fixed modeled and analyzed when subjected to two point loads at one-third span from each fixed support using the Finite Element Analysis software Ansys. The behavior of the analyzed beam has been observed in terms of flexural behavior, load-deflection responses, and crack pattern for various loading conditions until failure load. Keywords: Finite element analysis, ANSYS, flexural behavior, Reinforced Concrete (RC) beams, material non- linearity, shear reinforcement.

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49

Ciobanu, Robert, Octavian Donţu, Daniel Besnea, Alina Spanu, and Iulian Avarvarei. "Study for Improving Laser Beam Welding Efficiency." Applied Mechanics and Materials 811 (November 2015): 57–62. http://dx.doi.org/10.4028/www.scientific.net/amm.811.57.

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The aim of this paper is to highlight a method for improving laser beam efficiency. The laser weld bead profile depends on various parameters such as beam power, welding speed, wavelength of the laser radiation or the initial temperature of the material. Taking into account that laser beam welding efficiency is usually limited by synchronization of the laser source parameters, new methods were developed. In this paper is analyzed the influence of preheating the material and of the wavelength of laser radiation on the laser weld bead profile. Improvement in penetration depth was noted for preheating the material to around 140°C.

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50

Suciu, Mihaela. "About the Study of Bending Beam on Elastic Environment by Transfer-Matrix Method." Applied Mechanics and Materials 186 (June 2012): 149–55. http://dx.doi.org/10.4028/www.scientific.net/amm.186.149.

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The paper presents an analytical calculus for the bending beams on elastic environment. The elastic environment sends in all points a reaction force proportional to the deformation with the same constant of proportionality in all points. The calculus of the state vectors associated at the origin section and at the end section of the beam is made by Transfer-Matrix Method, putting the conditions on the supports (extremities) of the beam. After, we can calculate all state vectors for all sections of the beam.

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