scholarly journals Improvement of Cylinder Buckling Knockdown Factor through Imperfection Sensitivity

2013 ◽  
Vol 845 ◽  
pp. 226-230 ◽  
Author(s):  
Mohd Shahrom Ismail ◽  
B.T. Hang Tuah bin Baharudin ◽  
Zalaida Talib ◽  
Shariza Azwin Yahya
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Composite Cylinder ◽  
Imperfection Sensitivity ◽  
Design Guideline ◽  
Compression Load ◽  
Linear Finite Element ◽  
Load Carrying ◽  
Cfrp Composite ◽  
Geometrical Imperfections

This paper encompasses the work from numerical model by investigating the compression response of CFRP composite cylinder shells. The aim of this paper is to improve the reliability of NASA SP-8007 design guideline. The cylinder geometrical imperfections were tested through numerical modelling and validate with the experiment results. Good results comparison has been obtained through the work with small amount of errors. The cylinder shell load carrying capacity has been improved by average of 56% through imperfection study. This work builds confidence in the future use of non-linear finite element for the design of composite cylinder subjected to axial compression load.

Post-buckling Behavior of Stiffened Cross-Ply Cylindrical Shells

1994 ◽  
Vol 61 (4) ◽  
pp. 998-1000 ◽  
Author(s):  
M. Savoia ◽  
J. N. Reddy
Keyword(s):  
Axial Compression ◽  
Carrying Capacity ◽  
Shell Theory ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Buckling Modes ◽  
Geometric Imperfection ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Post Buckling

The post-buckling of stiffened, cross-ply laminated, circular determine the effects of shell lamination scheme and stiffeners on the reduced load-carrying capacity. The effect of geometric imperfection is also included. The analysis is based on the layerwise shell theory of Reddy, and the “smeared stiffener” technique is used to account for the stiffener stiffness. Nu cylinders under uniform axial compression is investigated to merical results for stiffened and unstiffened cylinders are presented, showing that imperfection-sensitivity is strictly related to the number of nearly simultaneous buckling modes.

STABILITY PROBLEMS OF STEEL‐CONCRETE MEMBERS COMPOSED OF HIGH‐STRENGTH MATERIALS

2010 ◽  
Vol 16 (3) ◽  
pp. 352-362 ◽  
Author(s):  
Zdeněk Kala ◽  
Libor Puklický ◽  
Abayomi Omishore ◽  
Marcela Karmazínová ◽  
Jindřich Melcher
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Carrying Capacity ◽  
High Strength ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Load Carrying ◽  
Geometrical Imperfections

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

Geometric Imperfection Sensitivity and Effect of Constraint Conditions of H-Section Columns under Compression

2010 ◽  
Vol 102-104 ◽  
pp. 140-144
Author(s):  
Yi Ping Wang ◽  
Yong Zang ◽  
Di Ping Wu
Keyword(s):  
Carrying Capacity ◽  
Steel Structures ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Geometric Imperfection ◽  
Manufacture Process ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Thin Walled ◽  
Tolerance Control

The buckling behavior of thin-walled steel structures under load is still imperfectly understood, in spite of much research over the past 50 years. In this paper, the buckling behaviors of H-section columns under compression have been simulated with ANSYS. In the analysis, contact pairs between column ends and end blocks have been introduced into the model, and the load carrying capacity of the columns with four kinds of end constraint conditions and various typical initial geometric imperfections has been calculated and discussed. The results indicate that the load carrying capacity is most sensitive to the flexural imperfection, and the constraint condition cannot change the imperfection sensitivity of a column under compression, but improving restrain condition can heighten the load carrying capacity. They are helpful to the use and the tolerance control in the manufacture process of thin-walled H-section steel structures.

Mechanical Properties of New Type Cold-Formed Steel Box-Shaped Component Welding Section Members

2013 ◽  
Vol 351-352 ◽  
pp. 601-609
Author(s):  
Sheng Wu
Keyword(s):  
Mechanical Properties ◽  
Carrying Capacity ◽  
Local Buckling ◽  
Bending Moment ◽  
Load Carrying Capacity ◽  
Unit Load ◽  
Compression Load ◽  
Section Modulus ◽  
Load Carrying ◽  
Cold Formed Steel

Cold-formed steel box-shaped section has the special features in both its mass center and moment center unification as double symmetry section and its outstanding advantage in moment and torsion rigidity. This paper presents a new kind of cold-formed steel box-shaped component welding sections, that is flanges opposite welding box-shaped component section DS. The mechanical properties such as buckling modes, load carrying capacity, rigidity, ductility and correlation curves of new section members which are subjected to axial compression, flexure, combined compression and bending have been analyzed by using nonlinear finite element method. The consumed steel quantities of per unit load carrying capacity between new section members and the same section dimensions of cold-formed C-section members have been compared systematically, too. Some conclusions can be drawn from above work that the DS section members have some superior properties, such as higher load carrying capacity and section modulus especially subjected to compression load, sufficient section stiffener and the sub-element local buckling hard to happen and so on. They are particularly suitable to withstand axial compressive loads, but also suitable to withstand the bending moment and bending loads. The consumed steel quantities are as almost 50% as the same dimension C-section members. The DS section members can go deep into the experimental study as to be used in the practical engineering.

scholarly journals Degradation of the EBR-CFRP strengthening system applied to reinforced concrete beams exposed to weathering

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Gláucia Maria Dalfré ◽  
Guilherme Aris Parsekian ◽  
Douglas da Costa Ferreira
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Natural Aging ◽  
Outdoor Exposure ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Externally Bonded ◽  
Cfrp Composite

Abstract Little is known about the behavior and durability of strengthening systems applied on concrete substrata and the possible loss of performance due to the degradation of the intervening materials by the structure’s natural aging process and exposure of the externally strengthened elements to aggressive environments. In this context, the present work presents an experimental analysis of the behavior of reinforced concrete beams strengthened with Carbon Fiber Reinforced Polymer (CFRP), applied according to the Externally Bonded Reinforcement (EBR) technique, maintained in a laboratory environment (indoor and protected) or exposed to weathering (outdoor exposure). In addition, specimens of the intervenient materials were also molded and exposed to the same environmental conditions as the beams. The results indicate that weather-exposed epoxy adhesives present reductions up to 70% in their mechanical properties after exposure, while the CFRP composite properties remain similar. It was also found that the strengthening system provided 50% and 28% increments in the load-carrying capacity and stiffness of the elements, respectively. However, the tests conducted after 6 months of weathering exposure showed a 10% reduction in the load-carrying capacity of the strengthened elements.

scholarly journals Behavior of Simply Supported Concrete Beam Using CFRP (Carbon Fiber Reinforced Polymer)

2021 ◽  
Vol 1197 (1) ◽  
pp. 012033
Author(s):  
Akshay Shivankar ◽  
K.R. Dabhekar ◽  
P.B. Patil ◽  
D.P. Mase ◽  
I.P. Khedikar
Keyword(s):  
Carbon Fiber ◽  
Flexural Strength ◽  
Double Layer ◽  
Carrying Capacity ◽  
Concrete Beam ◽  
Single Layer ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Cfrp Composite ◽  
Ultimate Load Carrying Capacity

Abstract The aim of this paper is to study the behavior of beam with the use of CFRP composite by experimentally and by ANSYS and compare both the results and compare load carrying capacity. For experimentally we cast Nine no’s of beam of size 100×100×400 mm, of M30 grade of concrete and curing for 7 days and after 7 days curing we conduct UPV test and find homogeneity of concrete beam and decided carbon fiber wrapping techniques we create two set of beam with 230 GSM wrapped with double layer and two set of beam with 430 GSM wrapped with double layer and two set of beam with 430 GSM wrapped with single layer, and 3 control beams without wrapping and test for flexural strength and by this test we observe the ultimate load carrying capacity and flexural strength of carbon fiber wrapped beam is increased as compare to control beams.

BOUNDARY SLIPPAGE FOR IMPROVING THE LOAD AND FRICTION PERFORMANCE OF A STEP BEARING

2010 ◽  
Vol 34 (3-4) ◽  
pp. 373-387 ◽  
Author(s):  
Yongbin Zhang
Keyword(s):  
Friction Coefficient ◽  
Carrying Capacity ◽  
Maximum Load ◽  
Load Carrying Capacity ◽  
Interfacial Condition ◽  
Design Guideline ◽  
Boundary Slippage ◽  
Load Carrying ◽  
New Type ◽  
Friction Performance

The present paper proposes a new type of step bearing by specifically modifying the interfacial condition between the fluid film and the bearing surface and introducing the boundary slippage at those interfaces. Analysis for the load-carrying capacity and friction coefficient is presented for this kind of bearing. The comparison of the obtained analytical results with the conventional (no-slippage) step bearing results shows that modifying the interfacial condition and introducing the boundary slippage at the specific bearing surfaces can significantly increase the load-carrying capacity and reduce the friction coefficient of a step bearing. Design guideline, the load-carrying capacity and the friction coefficient are also presented for this bearing at optimum condition which reaches the maximum load-carrying capacity.

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