Optimal design for thin-walled box beam based on material strength reliability

2003 ◽  
Vol 18 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Liu Gang
Keyword(s):  
Optimal Design ◽  
Material Strength ◽  
Box Beam ◽  
Thin Walled

scholarly journals Numerical/Experimental Validation of Thin-Walled Composite Box Beam Optimal Design

Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 111
Author(s):  
Enrico Cestino ◽  
Giacomo Frulla ◽  
Paolo Piana ◽  
Renzo Duella
Keyword(s):  
Optimal Design ◽  
Composite Structures ◽  
Experimental Validation ◽  
Torsional Stiffness ◽  
Beam Model ◽  
Angle Distribution ◽  
Structural Configuration ◽  
Box Beam ◽  
Thin Walled ◽  
Composite Box Beam

Thin-walled composite box beam structural configuration is representative of a specific high aspect ratio wing structure. The optimal design procedure and lay-up definition including appropriate coupling necessary for aerospace applications has been identified by means of “ad hoc” analytical formulation and by application of commercial code. The overall equivalent bending, torsional and coupled stiffness are derived and the accuracy of the simplified beam model is demonstrated by the application of Altair Optistruct. A simple case of a coupled cantilevered beam with load at one end is introduced to demonstrate that stiffness and torsion angle distribution does not always correspond to the trends that one would intuitively expect. The maximum of torsional stiffness is not obtained with fibers arranged at 45° and, at the maximum torsional stiffness, there is no minimum rotation angle. This observation becomes essential in any design process of composite structures where the constraints impose structural couplings. Furthermore, the presented theory is also extended to cases in which it is necessary to include composite/stiffened hybrid configurations. Good agreement has been found between the theoretical simplified beam model and numerical analysis. Finally, the selected composite configuration was compared to an experimental test case. The numerical and experimental validation is presented and discussed. A good correlation was found confirming the validity of the overall optimization for the optimal lay-up selection and structural configuration.

Computer analysis of thin-walled concrete box beams

1989 ◽  
Vol 16 (6) ◽  
pp. 902-909 ◽  
Author(s):  
Shahbaz Mavaddat ◽  
M. Saeed Mirza
Keyword(s):  
Key Words ◽  
Computer Analysis ◽  
Shear Stresses ◽  
Shear Lag ◽  
Applied Loading ◽  
Box Beam ◽  
Box Beams ◽  
Three Stages ◽  
Thin Walled ◽  
Normal And Shear Stresses

Three computer programs, written in FORTRAN WATFIV, are developed to analyze straight, monolithically cast, symmetric concrete box beams with one, two, or three cells and side cantilevers over a simple span or over two spans with symmetric mid-span loadings. The analysis, based on Maisel's formulation, is performed in three stages. First, the structure is idealized as a beam and the normal and shear stresses are calculated using the simple bending theory and St-Venant's theory of torsion. The secondary stresses arising from torsional and distortional warping and shear lag are calculated in the second and third stages, respectively. The execution times on an AMDAHL 580 system are 0.02, 0.93, and 0.25 s for the three programs, respectively. The stresses arising in each stage of analysis are then superposed to determine the overall response of the box section to the applied loading. The results are compared with Maisel's hand calculations. Key words: bending, bimoment, box beam, computer analysis, FORTRAN, shear, shear lag, thin-walled section, torsion, torsional and distortional warping.

Testing of Thin-Walled Tubular Workpieces

2016 ◽  
Vol 684 ◽  
pp. 483-486 ◽  
Author(s):  
S.G. Simagina
Keyword(s):  
Stressed State ◽  
Practical Importance ◽  
Complex Stressed State ◽  
Aviation Industry ◽  
Material Strength ◽  
Industrial Growth ◽  
Strength Performance ◽  
Wide Range ◽  
Physical Task ◽  
Thin Walled

In accordance with the Russian Federation State program called “Industrial growth and improving competitiveness” it becomes more wide-spread to use thin-walled makes for pieces, modern materials with new treating methods in mechanical engineering, in automobile production and modern aviation industry. As well as requirements for quality and mechanical characteristics of finished products constantly grow. In relation to these standards, methods of intensive irreversible deformation under conditions of complex stressed state are used with increasing frequency. Study of the following parameters has a great practical importance: loaded capability of the makes during exploitation and work material strength performance under complex production process. Such strain tasks are frequently counted as most complex and demand experimental verification because of geometric and physical task nonlinearity.The current study proposes testing method for thin-walled tubular workpieces which combines implementation simplicity with a wide range of strain-stressed state charts.

Optimal Design of an Elastic Column of Thin-Walled Cross Section

1968 ◽  
Vol 35 (2) ◽  
pp. 285-288 ◽  
Author(s):  
N. C. Huang ◽  
C. Y. Sheu
Keyword(s):  
Optimal Design ◽  
Cross Section ◽  
Wall Thickness ◽  
Cross Sections ◽  
Unit Length ◽  
Compressive Load ◽  
Median Line ◽  
Vertical Column ◽  
Thin Walled ◽  
Allowable Compressive Stress

This paper treats the optimal design of a vertical column that is built-in at the lower end. In addition to its own weight, the column is to carry an axial compressive load at its unsupported upper end. The column is to be designed as a thin-walled tube. The median line is to be the same for all cross sections; the wall thickness, though constant along the median line of any cross section, is allowed to vary along the length of the tube. Accordingly, the weight per unit length of the tube is proportional to the bending stiffness. For given length and total weight, the variation of the wall thickness along the column is to be determined to maximize the critical value of the compressive load at the upper end. The influence of a maximum allowable compressive stress on the design is also investigated.

Some studies on static analysis of composite thin-walled box beam

1997 ◽  
Vol 62 (4) ◽  
pp. 625-634 ◽  
Author(s):  
R. Suresh ◽  
S.K. Malhotra
Keyword(s):  
Static Analysis ◽  
Box Beam ◽  
Thin Walled

scholarly journals EXPERT SYSTEM TO CREATE BUILDING DESIGN SCHEME / EKSPERTINĖ SISTEMA STATINIO KONSTRUKCINEI SCHEMAI KURTI

2013 ◽  
Vol 5 (6) ◽  
pp. 601-604
Author(s):  
Žilvinas Steckevičius ◽  
Darius Mačiūnas ◽  
Elena Glėbienė ◽  
Renata Birbalaitė
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Expert System ◽  
Optimal Design ◽  
Finite Difference ◽  
Building Design ◽  
Material Strength ◽  
Design Elements ◽  
Design Scheme ◽  
Linear Load

In this paper the technology for creation of optimal design scheme for building is presented. Optimization of design scheme is based on genetic algorithm. Rectangular perimeter of single-storey structure with a linear load in all its locations is investigated. In such case, finite element, finite difference and other methods are not necessary – in order to evaluate the stress of design elements it is sufficient to use formulas of material strength. Santrauka Šiame darbe apžvelgta optimalios konstrukcinės schemoskūrimo technologija, naudojant genetinį optimizavimo algoritmą.Nagrinėjama stačiakampio perimetro vieno aukšto konstrukcijasu tolygiąja apkrova visose jos vietose. Šiuo atveju nebūtina naudotibaigtinių elementų, baigtinių skirtumų ar kitų metodų. Norintįvertinti konstrukcijos elementų įtempius, užtenka medžiagųatsparumo formulių.

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