Stochastic Risk Assessment for Structural Safety
Through the United States the structural safety of major and/or innovative structures has become a serious concern for engineers and to the general public. The objective of this paper...
Quantifying Quality Improvement Programs
Structural codes are evolving to a limit state design basis in which the safety checks are derived from the underlying probability distributions of strength and loads. An example safety...
Engineering Reliability: The Organizational Link
Organizational factors may significantly affect systems' reliability, but they are not typically included in modeling. This paper discusses how the stochastic models of system...
Rainflow Cycles in Nonstationary Gaussian Processes
This paper develops a methodology for calculating the probability distribution for rainflow cycles in a nonstationary Gaussian process. The up- and downcrossing rates are estimated for...
Stochastic Finite Element Analysis of Railroad Tracks
The loads acting on railroad tracks due to the passage of trains and the resisting track parameters have a random character. The purpose of this study is to incorporate the random parameters...
The First Passage Problem: Duffing Equation
The paper shows some simulation results for the response of the Duffing Equation to stationary Gaussian white noise. Results for the zero-start, double barrier, first passage problem of...
Reliability Study of Randomly Imperfect Beam-Columns
In this study, the effect of random initial geometric imperfections was treated as a set of equivalent random initial forces. This concept enables the direct employment of existing stochastic...
Efficient Probabilistic Structural Analysis Using an Advanced Mean Value Method
An advanced mean-value (AMV) method for probabilistic structural analysis is presented. This method blends the conventional mean value method with the advanced structural reliability analysis...
Markov Approximation to Fatigue Crack Propagation
The distribution of the time required by a crack to reach a specified length and the distribution of the crack size itself are determined. To this end, the fatigue crack propagation growth...
Parameter Identification in Markov Damage Models
This paper is concerned with the identification of parameters in cumulative damage processes whose underlying statistics are Markov. We consider the problem of parameter estimation during...
Diffusion Models of Crack Growth Due to Random Overloads
Stochastic diffusion models of crack growth are developed, reflecting uncertainty in applied loading and residual stresses near the crack tip. Applications are shown to (1) random vibration...
Challenges in Stochastic Structural Mechanics
Currently there are the emerging developments in stochastic computational mechanics, which includes stochastic finite elements and its applications in problems of random systems and random...
Nonstationary Random Vibration with REDUCE
Computerized symbolic algebra, in conjunction with the code REDUCE, is utilized in dealing with nonstationary random vibration of single-degree-of-freedom systems. Application of REDUCE...
Outcrossing Rates By Point Crossing Method
The point crossing method is applied to compute outcrossing rates for general safe domains, i.e., nonlinear load combinations problems. For stationary processes the method typically yields...
Stochastic Model for the Management of a Stream-Aquifer System
The management of a system of groundwater and surface water requires that the hydraulic connection of the two sources be investigated. The inherent uncertainties that exist in the data,...
Optimal Use and Economic Value of Seasonal Runoff Forecasts
Each year the National Weather Service and the Soil Conservation Service issue a monthly sequence of five (or six) categorical forecasts of the seasonal snowmelt runoff volume for 760...
Alternating Direction Oxidation Ditches?A Cost Saving Technology from Denmark
A soon to be released EPA report claims that in Denmark, small alternating direction oxidation ditches (ADOD) save as much as 70% of the cost for conventional oxidation ditches. The alternating...
Foam Over Troubled Toxics
Foams are now being used to control noxious vapor emissions from hazardous waste landfills. Another use of foams is in control of vapors emitted by chemical spills and fires. This article...
Speaking of RISK
With sensitivity, common sense and preparation, an engineer can explain risk effectively and fairly without alienating the public. Risk communicators should use a standard set of terms...
Biological Treatment of Hazardous Wastes
Biological treatment�using nature's bacteria and fungi�sometimes costs as little as 10-20% as incineration. Wastes in any form�solid, aqueous and gaseous�can be treated biologically....
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