Papers by Keyword: Probabilistic

Abstract: The evaluation of fatigue behavior of real components under service loading is important in reliability analysis. The present paper investigates the characteristics of two strain signals spectrum by using statistical inferences. The data used in this study are obtained from strain gauges installed on coil spring component of car suspension system driven over two different road surfaces. The coil springs are made of SAE 5160 carbon steel materials. The strain signals are explored to produce the summary statistics (i.e. root-mean-square, kurtosis, skewness etc.) and the rainflow cycle counting is performed to obtain total number of cycles and damage per cycle. Further, distribution fitting is applied to the cycle-counted strain ranges data. The results show that both signals fit well to a mixed Weibull distribution with three subpopulations.

Abstract: As wind power generation rapid development in china, wind power prediction is the key to the system operate safely. Given significant uncertainties involved in wind generation, probabilistic interval forecasting provides a unique solution to estimate and quantify the potential impacts and risks facing system operation with wind penetration beforehand. this paper based on the point forecast, calculate wind power prediction error, formulate the distribution of prediction error, you can get the historical probabilistic distribution of prediction error, use the distribution of error to build the risk assessment of wind power after prediction, give the fluctuate range of predicted values. Probabilistic interval forecasting can obtain the probably of power system operation safely and reliability assessment criterion.

Abstract: Significant progress has been made in the last years towards understanding the short and long – term performances of fibre reinforced cementitious materials and this has resulted in a number of novel and innovative uses. One of the main problems concerns the great quantity of random parameters– the placement of fibres, their orientation and quantity in a determined section etc. In consequence, full – probabilistic methods could be recommended for the analysis and evaluation of FRC. It can be assumed that for some structures probabilistic parameters derived from actual material tests could be used. A series of 9 specimens with the same reinforcement was used for a standard 4-point bending test. Using the obtained results, probabilistic normal distributions for the necessary input data were defined. The diagram of the experiment can then be recalculated probabilistically using the method SBRA. The ductility of the material can be expressed energetically. The final result is a histogram of the flexural toughness of the specimen that can be used for further calculations and evaluations.

Abstract: The accidents of truck crane happen frequently during working because of the structure failure of hoist boom, which result in severe economic loss and casualties. So, the method combining probabilistic and interval hybrid reliability theory with Bayesian Network is proposed to analyze the reliability of hoist boom structure. Probabilistic and interval hybrid model is built aiming at the interval variables and random variables to calculate the failure probability of hoisting boom under different conditions. Bayesian Network model is applied to calculate the importance index of different failure causes. In the end of the paper, practical example is given to illustrate the validity and efficiency of the present approach, which can provide basis for hoist boom design based on reliability.

Abstract: This study presents use of an approach which links the Latin Hypercube technique with Crank-Nicolson based finite difference approach for probabilistic assessment of chloride diffusion through silane-treated concrete. There are six random variables; (1) surface chloride, (2) diffusion coefficient, (3) first application time, (4) subsequent application time, (5) effective duration, and (6) cost of silane treatment. By different application times, three repair strategies are proposed. With silane treatment, the diffusion of chloride ions in silane-treated zone is retarded leading to the extension of the time which the chloride content at a threshold depth reaches the critical value of rebar corrosion and concrete cracking. Based on this extension, the time-dependent risk of rebar corrosion and concrete cracking is defined, and the time-dependent ratio of cumulative cost of silane treatment to benefit (percent reduction of the risk) is calculated. And, the best strategy based on the ratio of cost to benefit is justified.

Abstract: The objectives of this study are to determine the stress intensity factor (SIF) for different surface crack size of the lumbar vertebra and the probability of failure associated with finite element method. In this work, all the model components were meshed using the tetrahedral solid element. In order to simplify the model, all the spinal components were modeled as an isotropic and elastic material. Monte Carlo Simulation (MCS) technique was performed to conduct the probabilistic analysis using a probabilistic module in ANSYS with attempt for 100 trials. The results are observed that the maximum SIF were found in the end of crack path with 0.53 MPa.m^1/2 and the corresponding probability of failure for the model is 1.22%. Sensitivity analysis had been revealed that the crack size was sensitive to the maximum stress and maximum SIF output parameters with correlation 0.989 and 0.811 respectively. The current probabilistic study is useful as a tool to understand the inherent uncertainties and variations in biological models.

Abstract: A probabilistic method to durability is proposed for the design of reinforced cover of a concrete immersed in marine environment. It uses a non-linear chloride diffusion model for a saturated medium. Parameter variability is estimated and used by the probabilistic method to assess the probability of reaching a critical chloride concentration near the reinforcement for a given service life. Based on the concrete formulation and the cement chemical composition, the model parameters are evaluated with their associated random distribution.

Abstract: This paper presents the probabilistic analysis of surface crack in round bars subjected to tension stress using Monte Carlo Simulation (MCS). A probabilistic model based on an elastic finite element analysis (FEA) was developed to evaluate the failure probability obtained using a K-estimation method. This method is based on the stress intensity factor (SIF) where the failure occurred when the SIF was assumed to exceed the critical SIF. It was found that, the K-estimation method was adequate to evaluate the failure probability of the bars when compared with the results obtained using the probabilistic FEA approach. The advantage of K-estimation methods was the reduction of the computational time and cost significantly.

Abstract: In a noise environment probabilistic fuzzy clustering will force the noise into one or more clusters, seriously influencing the main dataset structure. We extend Type-1 membership values to Type-2 by assigning a possibilistic-membership function to each Type-1 membership value. The idea in building the Type-2 fuzzy sets is based simply on the fact that, for the same Type-1 membership value, the secondary membership function should make the larger possibility value greater than the smaller possibility value. This paper presents an efficient combined probabilistic and possibilistic method for building Type-2 fuzzy sets. Utilizing this concept we present a Type-2 FCM (T2FCM) that is an extension of the conventional FCM. The experimental results show that the T2FCM is less susceptible to noise than the Type-1 FCM. The T2FCM can ignore the inlier and outlier interrupt. The clustering results show the robustness of the proposed T2FCM because a reasonable amount of noise data does not affect its clustering performance.

Abstract: The most widely used method of liquefaction prediction are perform in deterministic process. The deterministic method according to seismic Chinese code is introduced by Z. CAO et al (2008). The deterministic method used the standard penetration test (SPT) to evaluate the liquefaction of soil. With this method, liquefaction of soil is predicted to occur if the factor of safety(FS), which in the ratio of critical SPT-N value(Resistance) over the actual measurement SPT-N(Load), is less than or equal to one. If the factor of safety greater than one, no soil liquefaction is predicted. Because the significant uncertainties in variable involved in the deterministic factor of safety, the probability method need to use. because the significant uncertainties in the random variables involved, the probabilistic method is needed to predict liquefaction. Probability of failure may be performed in which the liquefaction potential is assessed in term of probability safety factor (central safety factor). The study case is shown that the probabilistic method given the much more information for engineering decision than the deterministic method that given only the safety factor..