Nonlinear Bending and Collapse Analyses of a Poked Cylinder and Other Point-Loaded Cylinders

1983 ◽  
Vol 105 (4) ◽  
pp. 347-355 ◽  
Author(s):  
L. H. Sobel
Keyword(s):  
Carrying Capacity ◽  
Elastic Shell ◽  
Nonlinear Behavior ◽  
Displacement Curve ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Primary Interest ◽  
Nonlinear Bending ◽  
Load Carrying ◽  
Displacement Effects

Numerical results based on the STAGSC-1 finite element computer program are presented for the geometrically nonlinear behavior of cylindrical shells subjected to inward-directed radial point loads. Three elastic shell problems are considered: the poked cylinder (single load at midlength), which is the problem of primary interest, and the venetian blind and pinched cylinder, which are check cases. Load versus displacement curves obtained for the three problems reveal that geometric nonlinear (large displacement) effects are important. For the poked cylinder it is concluded that the maximum at the limit point of the load-displacement curve corresponds to a small local snapping of the cylinder that does not result in a loss of load-carrying capacity. The paper also discusses certain features of STAGSC-1 that should be helpful to users of the program.

Analysis of Load-Carrying Capacity of Thin-Walled Closed Beams with Different Slenderness

2014 ◽  
Vol 969 ◽  
pp. 39-44
Author(s):  
Jan Valeš
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Random Fields ◽  
Capacity Analysis ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Design Load ◽  
Steel Members ◽  
Load Carrying ◽  
Thin Walled

The presented paper deals with the load-carrying capacity analysis of compress steel members having the square closed (box) cross-section with non-dimensional slenderness 0.6, 0.8, 1.0 a 1.2. The axis of these beams is randomly three-dimensionally curved. Initial curvatures are modelled by random fields applying the LHS method. Load-carrying capacities are then calculated by the geometrically nonlinear solution using the ANSYS program. The results are presented both in form of histograms and of the table. The analysis of load-carrying capacity of beams with individual nonlinear slenderness is carried out, and the values are compared with the values of design load-carrying capacity according to the standard.

scholarly journals OPTIMIZATION OF GEOMETRICALLY NONLINEAR LATTICE GIRDERS. PART I: CONSIDERING MEMBER STRENGTHS

2015 ◽  
Vol 21 (4) ◽  
pp. 423-443 ◽  
Author(s):  
Tugrul Talaslioglu
Keyword(s):  
Optimization Algorithm ◽  
Carrying Capacity ◽  
Optimization Approach ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Load Carrying ◽  
Lattice Girder ◽  
Tubular Lattice

In this study, the entire weight, joint displacements and load-carrying capacity of tubular lattice girders are simultaneously optimized by a multi-objective optimization algorithm, named Non-dominated Sorting Genetic Algorithm II (NSGAII). Thus, the structural responses of tubular lattice girders are obtained by use of arc-length method as a geometrically nonlinear analysis approach and utilized to check their member strengths at each load step according to the provisions of the American Petroleum Institute specification (API RP2A-LRFD 1993). In order to improve the computing capacity of proposed optimization approach, while the optimization algorithm is hybridized with a radial basis neural network approach, an automatic lattice girder generator is included into the design stage. The improved optimization algorithm, called ImpNSGAII, is applied to both a benchmark lattice girder with 17 members and a lattice girder with varying span lengths and loading conditions. Consequently, it is demonstrated: 1) the optimal lattice girder configuration generated has a higher load-carrying capacity ensuring lower weight and joint displacement values; 2) the use of a multi-objective optimization approach increases the correctness degree in evaluation of optimality quality due to the possibility of performing a trade-off analysis for optimal designations; 3) the computing performance of ImpNSGAII is higher than NSGAII’s.

High Authority Morphing Structures

Aerospace ◽  
2003 ◽  
Author(s):  
Hilary Bart-Smith ◽  
Philip E. Risseeuw
Keyword(s):  
Drag Reduction ◽  
Carrying Capacity ◽  
Necessary Condition ◽  
Load Carrying Capacity ◽  
Equilibrium Equations ◽  
Primary Interest ◽  
Shape Morphing ◽  
Load Carrying ◽  
Linear Actuators ◽  
The Many

Recent advances in actuation technology and multifunctional materials have presented a unique opportunity to develop structures that have the ability to morph to a variety of shapes while under significant load constraints. One of the many applications of these “high-authority” systems is for morphing air wings for control and drag reduction. The exciting solution to this is the creation of a statically determinate structure that incorporates linear actuators to produce morphing capabilities. Statically determinate structures satisfy Maxwell’s necessary condition that the number of member forces equal the number of joint equilibrium equations. By imposing this condition on the structure it is possible to actively change the shape of the overall structure without resulting in failure. In a morphing foil, the only induced strain within passive members will be due to the hydrodynamic forces present. Deformation of the truss members is stretch-dominated—they do not experience bending—and thus improve the load carrying capacity of the structure. Of primary interest are Shape Memory Alloy (SMAs) actuators. SMAs are useful for shape morphing concepts where large forces are needed. A prototypical foil has been built around a statically determinate structure that incorporates linear actuators to produce morphing capabilities. These “smart” foils have been tested in a wind tunnel to examine their drag reduction capabilities.

scholarly journals An Inelastic Theoretical Model regarding the Load-Carrying Capacity of PSL Bending Component

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Baolu Sheng ◽  
Yuling Bian ◽  
Dong He ◽  
Aiping Zhou
Keyword(s):  
Theoretical Model ◽  
Compressive Stress ◽  
Carrying Capacity ◽  
Building Design ◽  
Load Carrying Capacity ◽  
Stress Strain ◽  
Nonlinear Bending ◽  
Nonlinear Stress ◽  
Load Carrying ◽  
Strain Relationship

Parallel strand lumber (PSL) is an attractive structural wood composite which may have prospective use in building constructions. Conducting nonlinear analysis for the bending of PSL beams is a critical step in the determination of ultimate strength and deflection of them, which is an essential requirement of the building design philosophy based on probability of ultimate state. For the purposes of this article, an inelastic theoretical model regarding the load-carrying capacity of the PSL bending component has been developed. Based on the uniaxial loading tests, the stress-strain behaviors of PSL composite in the grain direction were measured. 4-point bending experiments were also performed in this study to investigate the failure mechanism of the PSL components. The results show that the tensile stress-strain relationship of PSL materials in the grain direction remains linear until breaking, while the compressive stress-strain relationship exhibits nonlinear characteristics once the compressive stress exceeds the proportional limit, which can be expressed by a quadratic polynomial. The failure mode of the PSL beam can be summarized that the fibres in the top of the broken section were buckling and those in the bottom of the section were broken when failure occurred. Significant nonlinear behavior was exhibited based on the load-deflection curves of the PSL beams. To predict the nonlinear bending performance of the PSL beams, a theoretical model that could consider the nonlinear stress-strain relations of PSL and predict the damage modes of the PSL beams was developed. Well agreements can be observed between the results of calculations and experiments.

scholarly journals Probabilistic Verification of Structural Stability Design Procedures

2018 ◽  
Vol 12 (1) ◽  
pp. 283-289
Author(s):  
Zdeněk Kala
Keyword(s):  
Carrying Capacity ◽  
Stochastic Approach ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Nonlinear Solution ◽  
Design Load ◽  
Load Carrying ◽  
Eurocode 3 ◽  
Plane Frame ◽  
Buckling Length

Introduction: This contribution presents a comparison of three methods of the statistical computation of the design load-carrying capacity of a steel plane frame. Two approaches of the European Standard Eurocode 3 and one stochastic approach are applied. The stochastic approach takes into account the random influence of all imperfections and can be applied to the reliability verification of design according to Eurocode 3. Methods: The columns and beams in the steel frame are modelled with beam elements using the stability solution with buckling length and the geometrically nonlinear solution. The stochastic computational model is based on the geometrically nonlinear solution and on the random influence of initial imperfections, whose random samplings are simulated using the Monte Carlo method. Results and Conclusion: The design load-carrying capacity of the steel plane frame computed using the stability solution with buckling length is in good agreement with the stochastic solution in which the design value is calculated as 0.1 percentile. On the contrary, the geometrically nonlinear solution according to Eurocode 3 gives the lowest (safest) values of design load-carrying capacity.

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

Fuzzy Sets Theory in Comparison with Stochastic Methods to Analyse Nonlinear Behaviour of a Steel Member under Compression

2005 ◽  
Vol 10 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Z. Kala
Keyword(s):  
Fuzzy Sets ◽  
Carrying Capacity ◽  
Stochastic Methods ◽  
Nonlinear Behaviour ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Input Parameters ◽  
Stochastic Solution ◽  
Fuzzy Solution ◽  
Sets Theory

The load-carrying capacity of the member with imperfections under axial compression is analysed in the present paper. The study is divided into two parts: (i) in the first one, the input parameters are considered to be random numbers (with distribution of probability functions obtained from experimental results and/or tolerance standard), while (ii) in the other one, the input parameters are considered to be fuzzy numbers (with membership functions). The load-carrying capacity was calculated by geometrical nonlinear solution of a beam by means of the finite element method. In the case (ii), the membership function was determined by applying the fuzzy sets, whereas in the case (i), the distribution probability function of load-carrying capacity was determined. For (i) stochastic solution, the numerical simulation Monte Carlo method was applied, whereas for (ii) fuzzy solution, the method of the so-called α cuts was applied. The design load-carrying capacity was determined according to the EC3 and EN1990 standards. The results of the fuzzy, stochastic and deterministic analyses are compared in the concluding part of the paper.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

Load carrying capacity of cylindrical shells

2020 ◽  
Vol 2020 (21) ◽  
pp. 146-153
Author(s):  
Anatolii Dekhtyar ◽  
◽  
Oleksandr Babkov ◽  
Keyword(s):  
Carrying Capacity ◽  
Cylindrical Shells ◽  
Load Carrying Capacity ◽  
Load Carrying
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