Practices for Actions and Action-Effects Analysis in .NET Generation QR Code in .NET Practices for Actions and Action-Effects Analysis

How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
5.3 Practices for Actions and Action-Effects Analysis using .net framework tobuild qr code iso/iec18004 in web,windows application USS 93 in de ning such limit qr codes for .NET s even for structural behavior, other experts, such as machinery and equipment designers, will also need to be consulted. 5.

3 Practices for Actions and Action-Effects Analysis For SLS design of ship-shaped offshore units, in-service actions in terms of pressures or forces must be determined by vessel motion analysis based on site-speci c environmental data (e.g., waves, wind, currents) together with operational conditions (e.

g., loading, of oading), as previously described in 4. For limit-state design and assessment, it is essential to analyze the action effects of individual structural components, particularly in terms of working stresses.

Methodologies similar to those used for trading tankers can also be applied to the actioneffects analysis of ship-shaped offshore units. The nite-element method (FEM) is typically employed for such purposes. Regarding structural behavior, the following ve levels are often approximately considered: r r r r r Global structure (or hull girder) Cargo hold (or hull module) Grillage Frame and girder Local structure and details.

For each load case, t he resulting load effects are combined appropriately, using correlation factors relevant for the load case. The response at each level may provide the boundary conditions for the next lower-level analysis. The structural behavior being addressed may take the following forms: r Static or dynamic r Deterministic or probabilistic r Linear or nonlinear The analysis at each structure level may need to include a dynamic structural analysis, depending on whether that level of structure is subjected to any signi cant dynamic loads, that is, loads for which the shortest component period is the same order of magnitude or shorter than the longest natural period of that level of structure.

At the hull girder and cargo hold levels, a wave-excited dynamic analysis is usually not required for structures such as FPSOs, but a calculation of hull girder natural frequency is almost always necessary. It is interesting to note that a dynamic analysis may be required at hull girder and/or cargo hold levels for relatively exible trading ships, including some container vessels or naval ships that are susceptible to springing. At the principal member and local structure levels, a vibration analysis may be required if there are some signi cant and unavoidable sources of excitations (e.

g., machinery). In many cases, however, the preferred approach throughout the industry is to calculate the natural frequencies and to design the structure so as to avoid resonance.

When the characteristics of actions are certain, the deterministic analysis can be adopted, but the probabilistic analysis is usually required to characterize the. Serviceability Limit-State Design uncertainties and irr egularities associated with environmental and/or operational actions. For the practical purposes of limit-state design, the probabilistic characteristics of individual action-effect variables are identi ed separately, and then they are combined for limit-state assessment of the overall system structure together with the probabilistic characteristics of structural capacities. Environmental actions due to waves, wind, and currents can be complex, including the dynamic, probabilistic, and nonlinear characteristics in nature.

For simplicity, a linear analysis is often used under several simplifying assumptions. For example: (a) the irregular wave surface of the ocean can be represented as the linear sum of a large number of individual regular waves of different heights and frequencies; (b) the hydrodynamic forces on a vessel hull can be obtained using strip-theory simpli cations that, for certain parameters, consider each transverse section of the vessel separately and then combine the results linearly for the overall vessel; and (c) the wave force acting on each section may be assumed to be linearly proportional to the difference between the local wave height and the vessel s still-water-plane level. The accuracy of the rst two assumptions is usually satisfactory; however, the third is valid for vessels that are approximately wall-sided in the water-plane region.

If this is not so, or if there is any other source of nonlinearity, an appropriate nonlinear method of action-effect analysis should be employed. For a more detailed consideration of action-effect analysis for ship-shaped structures, see Paik and Hughes (2006). 5.

4 Elastic De ection Limits: Under Quasistatic Actions The hull of ship-shaped offshore structures may be subjected to signi cant longitudinal and vertical elastic distortions due to static loads, static load variations, and the dynamic effects of wind and waves. Under normal service conditions, the maximum de ection of structural components must not exceed certain acceptable limits per Eq. (5.

1b) for certain applications. The related load effects need to be accounted for in the equipment support structure that is likely to be affected. Total maximum de ections in speci c cases for example, for crane supports may be speci ed by equipment vendors.

This section presents useful analytical formulae of the maximum de ections for main types of structural components under quasistatic actions. We note that in classi cation society rules, it is not common to specify relative de ection limits for most major structural members within the hull except in special cases for example, at crane supports and in the vicinity of certain types of equipment. This is simply because some or many of such limits may be considered implicitly by other prescriptive aspects of the rules.

In designing a structure purely by rstprinciples-based procedures, however, one would need to de ne and consider those explicitly. 5.4.

1 Support Members In calculating the de ections for support members in a stiffened plate structure, illustrated in Figure 5.1, the attached plating must be considered with the support member, which is often called a plate-stiffener (beam) combination. Typical types of.

Copyright © . All rights reserved.