•The destructive effects of ignoring the damage curve in the optimal cable size selection problem is investigated.•A new method is presented to determine the optimal cross-section of cables taking ...into account their damage curves based on variable fault clearing times.•Overcurrent relays coordination is solved during long-term planning of distribution network with network changes to achieve optimal cross-section of cables.
The optimal selection of cable's cross-section in distribution networks reduces capital investment costs and network power loss. One of the important points in cable size selection process is taking the damage curve into account, which this curve depends on the type, insulation, and cross-section of cable. The cross-section should be selected in such a way that the cable can withstand short-circuit current until the fault is cleared. In conventional methods, damage curve is considered in optimal cable size selection (OCSS) process with assuming fixed times for fault clearing. In this paper, it is shown that this assumption makes two main issues: interference of cable's damage and overcurrent relay's characteristic curves in some branches, and unnecessary increase in capital investment costs in other branches. To overcome these challenges, a new method is proposed for solving OCSS problem using overcurrent relays coordination as sub-problem to obtain variable fault clearing times. The relays are coordinated with the worst-case conditions to ensure that network changes will not affect the results of OCSS in future. The results show the effectiveness of proposed method with the aim of capital investment costs reduction, and also interfering prevention between the cables damage and overcurrent relays characteristic curves.
•We discuss the current lifestyle designations of plant pathogenic fungi.•Host defenses may influence lifestyle transitions in hemi-biotrophs.•Sclerotinia sclerotiorum is not a typical necrotroph.•We ...discuss combining fungal lifestyle attributes with damage response curves.
Plants and fungi have had many years of friendly and not-so friendly competition for resources and quality of life. As a result, diverse pathosystems evolved numerous strategies, coupled with the emergence of multifaceted pathogenic and saprophytic lifestyles. We discuss fungal lifestyle classifications and how the views associated with certain fungal pathogens, particularly necrotophs, are changing as we learn more about the complexities of their interactions with a given host plant. We discuss the physiological events leading to the transition from biotrophy to necrotrophy in hemi-biotrophs, and conclude that both the control of plant immune responses and the need for a more efficient mode of nutrient acquisition are possible triggers for the transition to necrotrophy. Based on recent findings, we focus on the polyphagous plant pathogen Sclerotinia sclerotiorum. Rather than overwhelming plant foes, S. sclerotiorum has evolved clever means to compromise host recognition and establish disease, resulting in a broad and immensely successful pathogenic lifestyle. The tactics used by this fungus to achieve pathogenic success are being clarified. We propose that the hemi-biotrophic lifestyle may be more temporally and spatially complex than currently depicted, and that combining lifestyle attributes with damage response curves that consider the contribution of both the fungus and the host to pathogenesis, may provide a more holistic manner to view plant pathogens.
Spall damage is a typical damage mode of concrete structures under blast or high velocity impact loads. Blast and impact loads generate a stress wave propagating in the structure. At the opposite ...side from which the structural element is impulsively loaded, spall will occur if the net primary stresses over an area exceed the concrete dynamic tensile strength and the resistance force such as the material dynamic bond and interlock. Fragments of structural element generated from spall damage could eject with large velocities, and impose significant threats to equipment and personnel even it does not necessarily greatly reduce the load carrying capacity of the structural components. In the present study, spall damage of generic reinforced concrete columns subjected to blast loads is investigated numerically. Three-dimensional numerical models are developed to predict the concrete spalling under blast loads. The accuracy of the numerical simulations is verified with blast testing data reported by other researchers. Intensive numerical simulations are then carried out to investigate the influences of the column dimensions and reinforcement mesh on concrete spall damage. Based on numerical simulation data, empirical relations are suggested to predict concrete spall damage based on explosion scenarios, column dimensions and reinforcement conditions.
•Calibrated numerical model is used in the concrete spall simulation.•The proposed model well represents the concrete dynamic response to blast loads.•Damage curves and surfaces are generated based on extensive numerical investigations.
Precipitation changes caused by climate change are a phenomenon that may have far more serious consequences in urban areas than previously thought. Preventing the flood extent in rural and urban ...areas is crucial for the protection of human well-being and private and public land, and for the prevention of human casualties. Modeling potential floods and studying historic ones are key parameters to prevent damages from this natural disaster. European Union Directive 2007/60/EK obligated Member States to compile flood risk maps, showing the potential flood’s extent and depth. Using Cyprus river flood risk maps of the region of Larnaca, Corine land cover data, and open-access cadaster data, this study attempts to assess the economic damage. Cadaster data of buildings such as floor number and basement existence are incorporated in the damage functions used for flood recurrence intervals of 20, 100, and 500 years return periods. The study found that in the 500 year return flood period, 562 buildings would be potentially affected. The flood risk areas in the region of Larnaca consist of mainly urban (48%) and cultivation zones (50%), both economically important. The results suggest that economic damage assessment based on the applied data, combined with flood risk maps, can provide valuable information to disaster responders.
•The CCF tests were conducted on GH4169 alloy under stress-controlled condition.•A CCF damage curve is presented to establish a relationship between the LCF and HCF.•A fatigue life prediction model ...is proposed considering loading interaction.
In the present work, combined high and low cycle fatigue (CCF) tests were performed on GH4169 nickel-based alloy under stress-controlled conditions. The interaction between high cycle fatigue (HCF) and low cycle fatigue (LCF) results in a complex process of fatigue damage evolution under CCF loading. Based on the fatigue damage curve and the theory of equivalent damage, considering the interaction between HCF and LCF loading, a nonlinear cumulative damage model is proposed under CCF loading. The proposed model is deduced from the fatigue damage curve under CCF loading, which establishes a connection between the LCF and HCF damage curve. Three materials, including the other two materials, namely TC11 and Al 2024-T3, published in the relevant literature, are used to verify the proposed model. The experimental results demonstrate that the proposed model has better prediction results than those for Miner’s rule and the Trufyakov-Kovalchuk (T-K) model. The validation of the proposed model shows its superior performance.
•Assessing disaster losses at the watershed scale is a challenging task.•Quantitative assessment of flood damage can help managers grasp the basin conditions.•The flood risk curve helps watershed ...develop flood protection standards.•This article presents a combined riverine flood risk model to assess flood damage.
Climate change and rapid urbanization have exacerbated the occurrence and impact of floods. It is essential to carry out a quantitative flood risk assessment and manage the flood risk before a disaster occurs. This article presents a combined riverine flood risk model to obtain the exceedance probability loss (EPL) curve and expected annual damage (EAD) under the current climate. This model includes a rapid flood model and a flood damage model. It aims to simulate the flood risk and evaluate the flood damage at 10-, 30-, 50-, 100-, and 200-year return period events. The results show that: (1) The total inundation areas will sharply increase when the flood return periods are over 30 years. (2) The EAD is 1,476 million dollars in the Jiulong River Basin (JRB). When the flood return period is over 30 years, the total damage increases sharply. (3) The flood risk in the lower reaches of the JRB is higher than in the upper reaches when the flood event is beyond a 20-year return period. (4) Industrial sector damage is the largest, followed by tertiary industry, transportation, construction, agriculture, and infrastructure. The combined model chain can quickly assess the flood risk in the river basin and judge the flood risk in a watershed compared to the national level. In addition, it can be applied to other river basins, and it will provide actionable information for future flood risk management.
Through analyzing the characteristics of the Miner’s rule and the Manson-Halford (M-H) model, a nonlinear fatigue damage accumulation model is established based on the damage curve method under ...combined high and low cycle fatigue loading. In this model, an interaction factor related to the maximum stress and high cycle stress range is proposed to consider the loading interaction effect. Furthermore, the proposed model does not require any additional material parameters except for the S-N curve parameters. The experimental data of five materials, including TC11 alloy, 2024-T3 aluminum alloy, 45 steel, LY12-CZ aluminum alloy, and GH4033 Ni-based alloy, are introduced to verify the proposed model. Compared with the Miner’s rule and the M-H model, most of the prediction results by the proposed model are within the life factor range of 2, implying the established model has higher prediction accuracy.
Abstract
In recent years, flood risk map has been widely accepted as a tool for flood mitigation. The risk of flooding is normally illustrated in terms of its hazard (flood inundation maps), while ...vulnerability emphasizes the consequences of flooding. In developing countries, published studies on flood vulnerability assessment are limited, especially on flood damage. This paper attempts to establish a flood damage and risk assessment framework for Segamat town in Johor, Malaysia. A combination of flood hazard (flood characteristics), exposure (value of exposed elements), and vulnerability (flood damage function curve) were used for estimating the flood damage. The flood depth and areal extent were obtained from flood modeling and mapping using HEC-HMS/RAS and Arc GIS, respectively. Expected annual damage (EAD) for residential areas (50,112 units) and commercial areas (9,318 premises) were RM12.59 million and RM2.96 million, respectively. The flood hazard map shows that Bandar Seberang area (46,184 properties) was the most affected by the 2011 flood. The flood damage map illustrates similar patterns, with Bandar Seberang suffering the highest damage. The damage distribution maps are useful for reducing future flood damage by identifying properties with high flood risk.
The fatigue behavior of asphalt mixture is the main reason that affects the service performance and service life of asphalt pavement. The fatigue mechanism of asphalt mixture is still unclear. In ...fact, the fatigue damage of asphalt mixture is mainly related to the nature of asphalt binder. Therefore, the study of the damage of asphalt binder is beneficial to reveal the fatigue failure mechanism of asphalt mixture. At present, there is no clear damage behavior method of asphalt binder. Considering that the damage behavior of asphalt binder is actually related to its rheological behavior, the shear rheological method is used to evaluate the damage behavior of asphalt binder. The complex modulus is used as the evaluation index of asphalt damage behavior. Because the strain loading mode is consistent with the actual force of the binder in the asphalt mixture. The damage behavior of asphalt binder is studied by time scanning mode under controlled-strain mode. The influence of temperature, loading frequency, and other parameters on the damage behavior of asphalt binder is analyzed. Through the data analysis, the asphalt damage curve meets Boltzmann distribution. At the same time, the characteristics of asphalt damage curve are analyzed. It is proposed that there are three inflection points and two platforms for the typical damage curve of asphalt binder. The three inflection points divide the damage behavior of asphalt into elastic deformation stage, yield stage, crack growth stage, and failure stage. The effects of temperature and loading frequency on the curve characteristics are summarized. For asphalt binder with higher stiffness, the damage curve of asphalt binder is “L” type when the strain level and loading frequency are larger. When the temperature is higher, the loading frequency is smaller, and the strain is smaller, the damage curve will gradually change to anti-“S” type or even linear.
Removing masonry infill walls from the ground or lower stories of buildings to make more open spaces, may lead to forming soft-story structural irregularities. Since considering the masonry infill ...walls as non-structural components is a common assumption in the evaluation of the seismic demand of buildings, there is a lack of knowledge dealing with the influence of the soft-story effect on the seismic response. In this study, the performance of 4-, 8-, and 12-story moment-resisting reinforced concrete frames with and without a ground soft story is compared first. Then, a proposal including the use of a yielding dissipater device to retrofit soft-story buildings is presented. The low cost, the simple manufacturing technology, and the same behavior in tension and compression, which makes the new axial force not imposed on the columns, are some of the advantages of this device. In order to assess the seismic performance of the proposed system, incremental dynamic analysis was conducted on the frames. Five states were considered for each frame: (a) bare frame, (b) fully-infilled frame, (c) ground soft-story frame, (d) and (e) retrofitted frames with two different configurations of yielding dissipater devices in the ground soft story. The responses of the structures are compared in terms of capacity curves, progressive damage curves, inter-story drifts, and story damage values. The results demonstrate that the frames equipped with the yielding dissipater devices experience higher lateral load capacity, lower overall damage, lower drift, and a lower damage value in the ground story than the soft-story ones.
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