NUMERICAL METHOD OF CALCULATION OF ROUND PLATES IN A GEOMETRICALLY NONLINEAR STATEMENT

The article considers the axisymmetric problem about the calculation of round plates with dead loading in a geometrically nonlinear system. To solve the problem some generalized equations of finite difference method (FMD) are needed that allow to solve tasks within intergrable scope taking into account discontinuities of the required function, its first-order derivative and the right-hand side of the primitive differential equation. Resolvent differential equations of the question comprised fractionally the required function of the inflection and stresses are reduced to four differential equations, two of which are linear of the first-order and two are nonlinear of the second order. The obtained system of differential equations is solved numerically. The proposed method is shown with the example of calculation of a round plate; the given data are taken from work [1]. The calculation data with the minimum number of partitions are compared to the known solution of A.S. Vol’mir [1] and they indicate the possibility of using a numerical method for handling the problem in nonlinear statement.

Reliability Analysis on Slag Concrete Brick Masonry Compressed Based on Monte-Carlo Method

Slag concrete brick, as a kind of new materials utilizing wastes, is one kind of subsistent for clay brick. However, research on Slag concrete brick is very few, which restrains applying for slag concrete brick. By analyzing the reliability of the compress specimen with slag concrete brick masonry, the resistant statistic parameters are obtained and the computer probabilistic formula is established. Its reliability based on Monte-Carlo Method is calculated by means of Matlab. The result calculated is reasonable and reliable, which meets the requirement in rules. With the increasing of radio of live loading to dead loading, change tendency of reliability index of slag concrete masonry is that both sides are low and center is tall, and maximum appears between 0.5 and 1.0.

Manufacture Trial of Tensile and Compressive Creep Test Machine Both for Plate-Type Specimen and Round-Bar Specimen

This paper shows the concepts for creep test machine. Designed creep machine can be used for tensile dead loading or compressive dead loading for the specimens of plate-type and round-bar types. Applied temperature is up to 1000°C. The developed creep test machine can be applied under the action of dead loading, so that long time measurement is possible. The firm measurement stock shelf is used as the framework of keeping right angle maintenance. The obtained creep test machine is also expected to have the rigidity of long term use. The necessary devises are for general purpose to reduce the cost.

The Shear-Lag Effect on Curved Box Girder Bridge Considering Prestress and Initial Curvature

According to the principle of minimum potential energy and energy differential methods and assuming the shear lag warp displacement function with consideration of prestressed steel, a set of differential equations are deduced with different boundary conditions in considering moment, torsion, shear lag coupling. And the numerical solution of the differential equations is gained by Galerlein method. In addition, explores the influence on shear lag with prestressed force or not, dead loading, live loading and prestressed forces of the prestessed steels the areas of them basing on the model experiment and finite element model. Comparisons of results for typical numerical examples are given to verify the accuracy and applicability of the present method.

Study on Pretensioning Force of Wrapping Wires for Suspension Bridge Cables

The question of the pretensioning force of the wrapping wires for a suspension bridge is one of the important subjects. It could prevent the main cable from eroding by air or chemicals. And it must have some loss under the influence of dead loading, each mobile load and environment[1]. Now, the research of wrapping wire of the main cable is not much at home and abroad. And wrapping wire tension is mainly obtained depending on engineering experience. This paper has an experiment about the wrapping wire of Yangmingtan Bridge in Harbin to draw conclusions that wrapping wires tension which is 2m far from the cable clips is reduced extensively, more than 80%. But the residual tension, 8m from the cable clips, is about 35% of the initial tension. In addition, the wrapping wires tension which is about 93cm far from pre-wrapped wire-loops remains stable. Finally, starting from calculation theory, the paper puts forward that the wrapping wire tension should be 2.0kN.

Modeling of Initially Curved Beam Structures for Design of Multistable MEMS

This article describes a mathematical model and solution methodology for efficiently predicting the many equilibrium paths of an arbitrarily-shaped, pre-curved, clamped beam subjected to arbitrary dead loading. Such structures are common among multistable microelectromechanical systems (MEMS), and the presented model provides designers with an easy way to study the effects of loading, shape, and imperfections on beam behavior. Results are presented for switch and actuator applications motivated from the literature.

Numerical Stability Criteria for Localized Post-buckling Solutions in a Strut-on-Foundation Model

Some stability results are established for localized buckling solutions of a strut-on-foundation model which has an initially unstable post-buckling path followed by a restabilizing property. These results are in stark contrast with those for models with non-restabilizing behavior for which all solutions are unstable under dead-loading conditions. By approximating solutions with a nonperiodic set of functions, the stability of these static solutions can be assessed by examining the nature of the equilibrium using total potential energy considerations.