Papers by Keyword: Structural Failure

Abstract: Demand to increase safety for water transportation, namely ship is continuously rising as various accidental loads may threat condition of target structure, i.e. ship. Several possibilities of impact scenario can occur with various indenters, for example stranding to a grounded ice. In this work, a study of structural behaviour accounting for interaction between the ship structure and indenter is conducted. Numerical simulation is performed using finite element method to estimate damage extent of the double bottom. In analysis, the indenter for grounding scenario is applied by characteristic of the ice properties to obtain estimated response of the structure in experiencing impact on polar territory. Impact scenario is defined into three different locations, namely girder and space between two girders. Finally, tendency of the damage per destroyed component is summarized.

Abstract: This paper discusses issues related to the failure of steel bridge structures attributable to a certain type of fracture called Constraint Induced Fracture (CIF). It focuses on the causes of and factors associated with this phenomenon as it has been responsible for the failure of several bridges in the last dozen years. The strength aspects of the CIF phenomenon are analyzed using the example of the failure of the Hoan Bridge over the Milwaukee River in the US.

Abstract: This paper studies the multi-structural fault mode of satellite actuators, and use numbers of unknown parameters as fault indicators. The problem of adaptive state observer design for nonlinear systems with unknown parameters is dealt with by applying Lypunov method. The nonlinear object is firstly linearized into Lipschitz system, and then by analyzing the sufficient condition for asymptotic convergence of the observer, the structure of observer and the adaptive laws for parameter estimation are given. Finally, the adaptive observer is employed to estimate the faults of satellite actuator. Numerical simulation results show that this method is effective and able to quickly detect faults.

Abstract: Experimental and analytical studies are carried out to evaluate the response of an actual reinforced concrete structure following severe initial damage, which was caused in part by simultaneous explosion (removal) of four adjacent columns. In addition, two beam segments in the vicinity of the removed columns were also exploded. The structure resisted progressive collapse following such severe initial damage. The progressive collapse resisting mechanisms primarily included the axial-flexural action of the second floor deep beams and Vierendeel action of the flat plate system in floors above. In the analytical studies, a nonlinear model of the structure is used, which accounts for axial-flexural interaction of beams and slabs. The analytical results show good agreement with experimental data.

Abstract: Structural failure of a high pressure orifice flange of an oil refinery is studied by using visual inspection, optical and electron microscopy, tensile tests, fractography and stress calculation. This flange was located at a high pressure (2700 KPa), elevated temperature (370 C°) feeding pipe line. Failure observed during a startup at the time of increasing pressure and temperature. The results of the analysis show that brittle fracture has acted as a main factor for failure of the structure and stress concentration together with corrosion have provided minor sources for the failure. These results indicate that brittle behavior of this flange can attribute to hydrogen embrittlement of the steel material.

Abstract: Engineering design must be cost-effective over its complete life cycle and this necessitates a statistical approach to product and service reliability. A particular design therefore has a finite probability of failure during its lifetime and this has implications in terms of ensuring that design procedures, management of design, and operation and inspection are appropriate, effective and sufficient. Sophisticated expert system software packages have enabled wide access to rapid development to prototype and production stages. The expert knowledge encapsulated in such systems may be inadvertently used outside its intended application envelope, leading to unexpected and unwelcome failures. This paper highlights the role of failure analysis and fractography in the context of product reliability. It will present case studies illustrating typical structural reliability problems that highlight issues connected with the ‘reliability’ of experts in assessing the reasons for failure.