Performance Assessment of an Energy–Based Approximation Method for the Dynamic Capacity of RC Frames Subjected to Sudden Column Removal Scenarios

The alternative load path method is widely used to assess the progressive collapse performance of reinforced concrete structures. As an alternative to an accurate non–linear dynamic analysis, an energy–based method (EBM) can also be adopted to approximately calculate the dynamic load–bearing capacity curve or the dynamic resistance based on a static capacity curve. However, dynamic effects cannot be explicitly taken into account in the EBM. The model uncertainty associated with the use of the EBM for evaluating the dynamic ultimate capacity of structural frames has not yet been quantified. Knowledge of this model uncertainty is however necessary when applying EBM as part of reliability calculations, for example, in relation to structural robustness quantification. Hence, this article focuses on the evaluation of the performance of the EBM and the quantification of its model uncertainty in the context of reliability–based assessments of progressive or disproportionate collapse. The influences of damping effects and different column removal scenarios are investigated. As a result, it is found that damping effects have a limited influence on the performance of the EBM. In the case of an external column removal scenario, the performance of the EBM is lower as the response is not a single deformation mode according to the results in the frequency domain. However, a good performance is found in the case of an internal column removal scenario in which the assumption of a single deformation mode is found to be sufficiently adequate. Probabilistic models for the model uncertainties related to the use of the EBM compared to direct dynamic analyses are proposed in relation to both the resistances and the associated displacements. Overall, the EBM shows to be an adequate approximation, resulting in a small bias and small standard deviation for its associated model uncertainty.

Screening of retired lithium-ion batteries using incremental capacity charging curve based residual capacity estimation method for facilitating sustainable circular lithium-ion battery system

The rapidly growing deployment of lithium-ion batteries in electric vehicles is associated with a great waste of natural resource and environmental pollution caused by manufacturing and disposal. Repurposing the retired lithium-ion batteries can extend their useful life, creating environmental and economic benefits. However, the residual capacity of retired lithium-ion batteries is unknown and can be drastically different owing to various working history and calendar life. The main objective of this paper is to develop a fast and accurate capacity estimation method to classify the retired batteries by the remaining capacity. The hybrid technique of adaptive genetic algorithm and back propagation neural network is developed to estimate battery remaining capacity using the training set comprised of the selected characteristic parameters of incremental capacity curve of battery charging. Also, the paper investigated the correlation between characteristic parameters with capacity fade. The results show that capacity estimation errors of the proposed neural network are within 3%. Peak intensity of the incremental capacity curve has strong correlation with capacity fade. The findings also show that the translation of peak of the incremental capacity curve is strongly related with internal resistance.

Distal learning of the incremental capacity curve of a LiFePO4 battery

An intelligent model of the incremental capacity (IC) curve of an automotive lithium-ferrophosphate battery is presented. The relative heights of the two major peaks of the IC curve can be acquired from high-current discharges, thus enabling the state of health estimation of the battery while the vehicle is being operated and in certain cases, aging mechanisms can be suggested. Our model has been validated using a large dataset (number of batteries) representing different degradation scenarios, obtained from a recently available open-source database.

Analisis Kapasitas Lateral Pada Fondasi Tiang Tunggal Dan Tiang Kelompok Pada Tanah Pasir

Fondasi ialah bagian dari suatu sistem rekayasa yang meneruskan beban yang ditopang oleh fondasi dan beratnya sendiri kedalam tanah dan batuan yang terletak dibawahnya. Pada jurnal ini, dilakukan analisa kapasitas lateral tiang tunggal dan tiang kelompok pada tanah pasir. Untuk dapat menganalisis tiang pancang tunggal dan tiang kelompok pada tanah pasir dalam kondisi elastic dapat dilakukan dengan metode analisis statik non linier atau analisis pushover. Analisis pushover adalah prosedur analisis untuk mengetahui keruntuhan suatu bangunan dengan memberikan suatu pola beban statik tertentu dalam arah lateral yang besarnya akan ditingkatkan secara bertahap sampai struktur tersebut mencapai target displacement tertentu atau mencapai pola keruntuhan tertentu. Dari hasil analisis pushover terhadap suatu tiang dihasilkan kurva yang menghubungkan antara base shear dan roof displacement atau disebut kurva kapasitas. Dari kurva kapasitas tersebut dapat dilihat perilaku suatu tiang dari kondisi elastis sampai plastis hingga mengalami kegagalan. Dengan adanya kurva kapasitas yang diperoleh, kita dapat melihat tingkat kinerja suatu tiang berdasarkan metode spektrum kapasitas berdasarkan peraturan ATC-40 dan Pushover Analysis of Underground Structures. The foundation is part of an engineering system that forwards the burden supported by the foundation and its own weight into the soil and rocks beneath. In this journal, an analysis of the lateral capacity of single piles and group piles is carried out on sandy soil. To be able to analyze a single pile and group piles on sandy soil in elastic conditions can be done by non-linear static analysis or pushover analysis. Pushover analysis is an analysis procedure to determine the collapse of a building by providing a certain static load pattern in the lateral direction whose magnitude will be increased gradually until the structure reaches a certain displacement target or reaches a certain collapse pattern. From the results of pushover analysis on a pile, a curve that connects the base shear and roof displacement is called a capacity curve. From the capacity curve, it can be seen the behavior of a pile from elastic to plastic conditions to failure. With the obtained capacity curve, we can see the level of performance of a pile based on the capacity spectrum method based on ATC-40 regulations and Pushover Analysis of Underground Structures.

Simplified Hazard Modeling and Structural Reliability Analysis Considering Non-Synoptic Wind Systems (NSWS) in Canada

High-intensity wind events such as tornadoes and downbursts can be very destructive to structures and infrastructure systems. In the present chapter, an overview of the assessment of the wind hazard due to tornadoes and downbursts for Canadian sites is provided. Available tornado occurrence information available in Canada that can be used as the basis to develop a tornado occurrence model is discussed. The chapter presents an overall framework to develop tornado wind-velocity hazard maps for Canada. It also explores the use of simple equivalent along height wind profile that could be used to evaluate tornadic wind loading for line-like structures and of a practical procedure to evaluate the failure probability of structures subjected to high-intensity wind events. It is indicated that for a certain class of prismatic structures, the use of nonlinear static pushover analysis can be adequate to evaluate the capacity curve of the structure subjected to downburst wind loading. A probabilistic model of the capacity curve obtained in such a manner can then be used to evaluate the structural reliability by incorporating the assessed wind-velocity hazard map and equivalent wind profile.