I m
and the number of cycles within the sea state of period 7j is Nonlinear effects due to large amplitude motions and large waves can be neglected in the fatigue assessment since the stress ranges at lower load levels contribute relatively more to the cumulative fatigue damage. In cases where linearization is required, it is recommended that the linearization is performed at a load level representative of the stress ranges that contribute the most to fatigue damage, i.e. stresses at probability...
Loss of Cargo
Loss of cargo occurs in many marine accidents. Usually the shipper obtains insurance for the transport of cargo, and in case of a loss, the shipper will be directly compensated by the insurer. Reimbursement of the value of the cargo is normally the extent of the consequences. In some cases, where the time to deliver the cargo is critical, reimbursement of the value of cargo may not compensate the shipper for the total consequences of the loss. The intangible part of the loss is difficult to...
Stiffener
Figure 7.1 Stiffened Panel NTS, 1998 Figure 7.1 Stiffened Panel NTS, 1998 plate stiffening upon the ductility of the structure should not be overlooked. Furthermore, if detailed stiffening is added, the analyst should consider the fabrication and inspection consequences of stiffening. For examples, the questions may be given Can the welder get sufficient access to the area , Will the weld type be limited e.g. only single sided welding possible , Will the weld detail cause a local stress...
10
Figure 3.1S Long-term Extremes of Dynamic Stress Responses for Deck Plate return period 20,50, and 100 years Zhao, Bai amp Shin, 2001 3.5.4 Prediction of Most Probable Maximum Extreme for Non-Gaussian Process For a short-term Gaussian process, there are simple equations for estimating extremes. The Most Probable Maximum value mpm , of a zero-mean narrow-band Gaussian random process may be obtained by Eq. 3.6 , for a large number of observations, N. In this Section, we shall discuss the...
K
The MPME typically corresponds to an exceedance probability of 1 1000 in a distribution function of individual peaks or to 0.63 in an extreme distribution function. The MPME of the response can therefore be calculated as Now the key is to estimate the parameters y and k based on the response signal records obtained from time-domain simulations. The SNAME Bulletin recommends to extract maximum simulated value for each of the ten 3-hour response signal records, and to compute the parameters by...
Part IV Structural Reliability Dzx
Chapter 26 Reliability-Based Design and Code Calibration The most important applications of structural reliability methods is perhaps reliability-based design and calibration of the safety factors in the design codes. These two topics will be addressed in detailed in this chapter. In structural design, there are always uncertainties involved in determining loads and capacities. Historically, the engineering design process has compensated for these uncertainties by the use of safety factors....
Info Kut
Figure 17.4 Stress Distribution at an Attachment and Extrapolation of Stresses NTS, 1998 The notch stress approach is based on the determination of peak stress that account for the weld profile. The notch stress is therefore estimated as the product of the hot-spot stress and rhe stress concentratio factor for weld profile so-called weld concentration facyor . The weld concentratio factor may be estimated from diagrams, parametrci equations, experimental measurements and finite element...
M
It is seen from the above tow equations that the evaluation of the failure probability of series and parallel systems amounts to evaluation of the standard multi-normal integral. This is however a difficult task for problems of large dimensions. To demonstrate the reliability calculation of a simple parallel system, an example is given in Section 23.11. 23.6 Combination of Statistical Loads 23.6.1 General In general, loads can be grouped into the following three classes based on statistical...