Safety Design Research Articles

Consideration of quantitative risk reduction and risk achievement measures in safe NPP design

Abstract In the models developed by probabilistic safety analyses (PSA) and in their applications associated with nuclear power plants (NPPs), the risk importance of a particular feature can be, most generally, divided into two categories: importance with respect to the risk-increase potential and importance with respect to the risk-decrease potential. A representative measure of the first category is risk achievement worth (RAW), while a representative measure of the second category is risk reduction worth (RRW). The present paper discusses the use of RAW and RRW in achieving safe design and points out some implications of their mutual dependency on the selection of a risk-reduction strategy. A simple example is provided to illustrate the differences between the two basic strategies and point out to the main issues and conclusions.

Research on safety design of transport packaging for lithium battery products

Abstract In view of the characteristics of dangerous goods exported by lithium batteries, the safety norms of lithium battery transport packaging stipulated by international technical regulations are sorted out, and the performance requirements of dangerous goods packaging for export lithium batteries are studied. Based on the overall safety design and protection of this kind of dangerous goods packaging, the design scheme of lithium battery tray protection and carton packaging is proposed. A drop simulation test is carried out to analyze and evaluate the design scheme.

Javascript And WordPress Are Used In A Structural Engineering Applications

Abstract : In the realm of structural engineering, efficient software tools are essential for designing, analyzing, and managing various types of structures. The integration of WordPress, HTML, CSS, and PHP offers a unique opportunity to develop a versatile structural engineering software platform. This software aims to provide structural engineers with an intuitive and customizable toolset to streamline their workflow and enhance productivity. Structural design software and structural analysis software can significantly increase the effectiveness and precision of engineering projects in several ways. These tools give engineers a powerful platform to model and visualise complex structures in a virtual environment, allowing them to detect potential flaws or weaknesses before building in reality and preventing costly errors. Also, thestructural design software makes it possible for engineers to optimise designs for maximum efficiency and safety by precisely analysing various load scenarios.

Industrial heritage restoration/renovation projects and their societal impacts: Case of Gasholder Restoration Projects

The refurbishment of industrial heritage structures offers economic benefits and provides future generations with an insight into the industrial history of cities. However, industrial heritage projects possess unique attributes and risks, and the procedures for restoring, renovating, and converting these structures differ from those of other construction projects and their impacts to society. From the view of Social Impact Management, ISO 45001, ISO 14001, ISO/DIS 14001 and similar standards directly related with the sustainability. However, the design and method of construction are also important not only for workers’ safety but also public health and safety. For a holistic view Building Information Modeling provides us to gather information to reduce these concerns. This short communication covers societal impacts of a recently completed project in Germany that titled as Building Information Modeling (BIM) based sustainability, facility management and design for safety of industrial heritage buildings restoration/renovation projects and tries to put forward health and safety risks of Gasholder Restoration Projects to workers as well as to public during the project and after the completion by the aid of on site observations and expert panel discussions.

Experimental study of capacity fading mechanism in multiple overdischarge on LiNi0.5Co0.2Mn0.3O2&LiMn2O4/graphite lithium-ion batteries

Batteries can be overdischarged in practical applications, which does not pose safety risks. However, overdischarge can have a significant impact on battery performance. In this work, LiNi0.5Co0.2Mn0.3O2 (NCM)&LiMn2O4 (LMO)/graphite batteries are used as the main body. The failure mechanism of the batteries under different temperatures (−10 °C, 25 °C, 45 °C) and different depth of discharge (DOD) (105 % DOD and 110 % DOD) is studied systematically through the electrochemical methods, scanning electron microscopy (SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that the deep overdischarge and high temperature accelerate the degradation of electrolyte, separator and collector, and cause rupture and recombination of solid electrolyte interphase (SEI) film. These result in the loss of conductivity, active substances and lithium ions, in which the loss of lithium ions plays a dominant role. Moreover, the attenuation of positive active material mainly comes from NCM. Our research results are of great significance for researchers to understand the failure mechanism of lithium batteries under different conditions and can provide important guidance for the safe design of lithium-ion batteries.

Quantitative assessment of the extent of damage to timber structures during the full course of a real fire using the energy equivalence method

In this study, an innovative method, the Energy Equivalence Method (EEM), is proposed in the context of the Performance-Based Fire Engineering (PBFE) framework for quantitatively assessing the degree of damage of timber structures during the full process of a real fire. To verify the validity of the method, glued laminated timber (GLT) specimens and GLT columns were selected as the subjects of fire action, and a series of equivalent fire experiments were conducted by using a parametric fire model (referred to as the DNI fire model), which is currently used in Germany, to simulate real fire scenarios. By comparing the equivalence of charring depth (CD), pyrolysis zone temperature, and residual load-carrying capacity of the test specimens after the action of the DNI fire and its equivalent standard fire, the validity of the EEM in quantifying the degree of damage to timber members after the DNI fire was fully verified. Subsequently, based on the fire experimental data, accurate thermal and structural models were developed, and these models were utilized to further validate the effectiveness of the EEM in quantifying the extent of damage to timber members under the action of a DNI fire over an arbitrary time period. The results of the study show that the proposed EEM not only can be used to assess the extent of structural damage during fire action and the residual load carrying capacity of the structure after fire action, but also promotes the transition from standard fire safety design to the PBFE design.

A framework recommendation for updating running safety design criteria of non-ballasted railway bridges using statistical investigations

A framework recommendation for updating running safety design criteria of non-ballasted railway bridges using statistical investigations

Research on cascading effect analysis of civil aircraft electrical power system failures

Abstract Cascade effect analysis is a qualitative analytical method recommended by SAE ARP 4761A [1] for evaluating complex integrated civil aircraft systems. The Electrical Power System (EPS) is one of the critical onboard systems. It can provide electrical power to the avionics system, flight control system, and other critical systems on the aircraft, and it has a wide range of failure effects. The consequences of EPS failure effects are difficult to determine. This paper applies the cascading effect analysis method to carry out the qualitative safety assessment of the EPS on the aircraft and finally confirms that the architectural design of the EPS met the safety design requirements. It also gives the engineering method (such as test, MBSA) suggestion to further check and verify the correctness and completeness of the theoretical analysis of CEA.

System-Level Magnetic Interference Modeling in Electrified Monorail System for Track-Side Safety Design

System-Level Magnetic Interference Modeling in Electrified Monorail System for Track-Side Safety Design

Traffic safety comprehensive evaluation of urban tunnel visual guiding system based on extension matter-element model: a case study in tunnel curves

Objective The visual guiding system, as a tunnel traffic safety improvement method by using visual guiding facilities to actively guide driving safely, has been widely used in countries with many tunnels, in recent years. This paper aims to quantitatively study the comprehensive evaluation of traffic safety of the visual guiding system in tunnels, which has certain engineering application value and can provide support for the quantitative evaluation and optimal design of tunnel traffic safety. Methods Based on the analysis of the relevant factors of urban tunnel traffic safety, a multi-factor comprehensive evaluation system with 5 upper-level indicators and 12 basic-level indicators was proposed. Considering the independent and incompatible indicators, a comprehensive evaluation method of traffic safety of the visual guiding system in urban tunnels was constructed by using the extension matter-element model. Taking the scene of 4 types of tunnel curves, such as no facilities, horizontal stripe, chevron alignment sign, and LED arch, as examples, the comprehensive evaluation of various schemes were carried out by using simulation tests. Results The traffic safety comprehensive evaluation system of visual guiding system in urban tunnels can be analyzed from five aspects: perception reaction, guidance ability, driver factor, driving task, and facility appearance. The results demonstrated significant the comprehensive evaluation result of the target level of scene 1 was L4, scene 2 was L3, scene 3 was L2, and scene 4 was L1. That is, the final results of the comprehensive evaluation of the four scenes were poor, medium, good, and very good, respectively. Conclusions In the scheme of visual guiding system for urban tunnel curves, the effectiveness of the three types of designs, from high to low, was the LED arch, chevron alignment sign, and horizontal stripe, and the safety of the scene without facilities was the lowest. Hence, setting the LED arch in the urban tunnel curve has a good effect in the aspects of guidance ability, sight distance, and sight zone, and is conducive to the driver’s perception reaction and driving task.

Safety profiling of technical lignins originating from various bioresources and conversion processes

In this work, a set of eight technical lignin samples from various botanical origins and production processes were characterized for their chemical composition, higher heating value, size distribution, dust explosion sensitivity and severity, thermal hazard characteristics and biodegradability, in further support of their sustainable use. More specifically, safety-focused parameters have been assessed in terms of consistency with relating physico-chemical properties determined for the whole set of technical lignins. The results emphasized the heterogeneity and variability of technical lignins and the subsequent need for a comprehensive characterization of new lignin feedstocks arising from novel biorefineries. Indeed, significant differences were revealed between the samples in terms of hazards sensitivity. This first comparative physico-chemical safety profiling of technical lignins could be useful for the hazard analysis and the safe design of the facilities associated with large scale valorisation of biomass residues such as lignins, targeting “zero waste” sustainable conversion of bioresources.

Experimental Investigation of Lithium-Ion Batteries Thermal Runaway Propagation Consequences under Different Triggering Modes

In the stage of aircraft development and airworthiness verification, it is necessary to master the influence of lithium-ion battery (LIB) thermal runaway (TR) propagation. In this paper, the battery TR propagation behavior under different trigger positions and modes is studied experimentally, and the calculation and comparison are carried out from the parameters of real-time temperature, voltage, propagation speed, total energy released, and solid ejecta. When the two adjacent cells at the top corner, side, and center of the module are overheated, TR occurs at about 1000 s for the triggered cells, while the whole-overheating trigger mode takes a longer time. The latter’s transmission speed is extremely fast, spreading 2.67 cells per second on average. The heat generated by the solid ejecta of the whole-overheating trigger mode is 82,437 J, which is more destructive. The voltage of the triggered cell fluctuates abnormally in a precursor manner when the internal active substances in the cell undergo a self-generated thermal reaction. This work can provide a reference for the safety and economical design of system installations and the correct setting of airworthiness verification Method of Compliance (MoC) experiments to verify whether the aircraft can bear and contain the adverse effects caused by LIB TR.

High-Accuracy and Fast Calculation Framework for Berthing Collision Force of Docks Based on Surrogate Models

The accurate prediction of the collision force magnitude resulting from ship berthing on docks is crucial for the rationality and safety of dock structural design. This paper presents a novel framework for the calculation of berthing collision force for ships (CBCF), which integrates field data, finite element models, and surrogate models. Based on field data and finite element analysis, the framework constructs and compares four surrogate models with low sample requirements, ultimately selecting the optimal surrogate model for predicting collision force. Furthermore, a sensitivity analysis of the parameters is conducted based on the selected model, followed by a comparison with the various methods used for collision force prediction. The results illustrate the effectiveness of the proposed framework in replacing finite element models for the rapid and accurate prediction of collision force. Comparison with existing methods also underscores the advantages of the proposed framework, including low sample requirements, high calculation accuracy, and exceptional efficiency. In summary, this study not only introduces a novel and precise surrogate model framework for the swift prediction of berthing collision force, but it also offers valuable insights into the prevention of ship collision with wharf accidents and facilitates the rational and safe design of wharf structures.

A probabilistic selection of fire scenarios considering operating condition in aircraft carrier’s hangar spaces

ABSTRACT Aircraft carrier hangars require sufficient space to enable essential functions such as aircraft preparation, stowage, handling of aviation fuel and munitions, etc. Consequently, the hangars are treated as high-fire-risk spaces owing to their operating conditions. Although hangar fire accidents are caused by various temporally and spatially varying fire hazards, fire safety designs for hangars follow a deterministic approach based on IMO regulations, similar to ro-ro ships. Hence, this paper proposes one hundred credible fire scenarios to enhance the fire safety design of hangar structures by utilizing Latin hypercube sampling. These fire scenarios were also employed to determine fire-induced loads in the form of exceedance curves. Moreover, the effect of fire frequency defining method and ship motions on fire consequences was quantitatively investigated through case study and CFD simulation.

Probabilistic Prediction of Floating Offshore Wind Turbine Platform Motions via Uncertainty Quantification and Information Integration

The accurate prediction of short-term platform motions in a real environment is crucial for the safe design, operation, and maintenance of floating offshore wind turbines (FOWTs). Numerical simulations of motions are typically associated with high uncertainties due to abstracted theoretical models, empirical parameters, initial environment parameters, etc. Therefore, it is necessary to integrate other sources of information associated with less uncertainty, e.g., monitoring data, for accurate predictions. In this paper, we propose a probabilistic prediction based on the Bayesian approach that logically integrates motion monitoring data with simulated motion predictions of FOWTs, considering uncertainties in the environment model, structural properties, motion prediction method, monitoring data, etc. The approach consists of constructing a prior probability density function (PDF) of a random variable (which characterizes the largest value of the initial motion response) via numerical simulations and a likelihood function based on platform motion monitoring data and deriving a posterior PDF of the random variable by Bayesian updating. Then, posterior distributions of short-term extreme motion responses are derived using the posterior PDF of the random variable, representing lower uncertainty and improved accuracy. A Metropolis–Hastings algorithm is adopted to obtain PDFs of complex probability distributions. The effectiveness of the approach is demonstrated on a real FOWT platform in Scotland. The proposed probabilistic prediction approach results in posterior distributions of short-term extreme platform motions associated with less uncertainty and higher accuracy, which is attributed to integrating prior knowledge with monitoring data.

Experimental and Numerical Investigation of the Fracture Behavior of Extruded Wood-Plastic Composites under Bending.

The ability of wood-plastic composites (WPCs) to withstand various loads and resist plastic failure is attracting more and more interest due to the global increase in demand for WPCs by over 6 million tons per year. Among the most important and innovative research methods are those based on fracture mechanics-their results enable material designers to optimize the structures of these hybrid polymer composites at the nano, micro and macro levels, and they allow engineers to more accurately evaluate and select functional, sustainable, long-lasting and safe product designs. In this study, standard single-edge notched bending (SENB) tests were used to analyze the fracture toughness of two different extruded WPCs along the longitudinal (L) and transverse (T) directions of extrusion. In addition to their resistance to crack propagation, critical fracture criteria, initial contact stiffness, fracture parameters and fracture surfaces, the mechanical properties of these composites were also investigated. The results showed that WPC-A coded composites withstood higher loads until failure in both directions compared to WPC-B. Despite the larger data spread, both types of composites were more resistant to crack propagation in the T direction. Mode II of crack propagation was clearly visible, while mode III was not as pronounced. The experimental results and the numerical finite element (FE) model developed up to 58% of the maximum load correlated well, and the obtained deformation curves were best approximated using cubic equations (R2 > 0.99). The shear stress zone and its location, as well as the distribution of the equivalent stresses, had a major influence on crack propagation in the fracture process zone (FZP).

A Simultaneous Usage Ratio Based on Occupant Behavior: A Case Study of Intermittent Heating in an Apartment Building in Japan

It is important to reduce the building load and downsize the heat source equipment capacity during construction or renovation carried out toward the achievement of carbon neutrality by 2050 in Japan. However, this sometimes results in the oversizing of the heat source equipment capacity, despite the fact that designers are engaged in the implementation of safety designs while attempting to balance between cost and risk. This study investigated the simultaneous usage ratio of heating based on occupant behavior in an apartment building with the aim of optimizing this capacity. This ratio was defined as a peak load-based approach rather than simultaneity based on the number of people using the system. First, the analysis was conducted for the heating load characteristics for each dwelling unit and each household composition. The subject of this case study was an apartment building located in Sapporo, Japan. Based on these data, a method for creating the curve of the simultaneous usage ratio to avoid a combinatorial explosion was suggested. As a result, the ratio created for about 200 dwelling units was 53.6% in an apartment building and generally stabilized when the number of dwelling units exceeded 30. Finally, a case study was attempted to analyze the influence of changes in household composition on the ratio. If the method proposed in this study for creating the curve of simultaneous usage ratios were to be applied in not only this case study but also in case studies of non-residential buildings such as offices, new results about the curves of ratios that differ from those of apartment buildings could be obtained. Therefore, this case study provides a methodology for statistically quantifying the simultaneous usage ratio as one of the factors in determining the appropriate heat source equipment capacity in the design stage.

Healthcare Waste Management Policy in a lower-middle-income country: A case for the adoption of the RADICAL framework

The COVID-19 pandemic raised the salience of Healthcare Waste Management (HCWM). Various studies have shown that the level of HCWM in lower-middle-income countries falls below international standards and global best practice, indicating that the national policy on HCWM is either non-existent or has not been embedded in practice. The renewed salience affords an opportunity to revisit, update and embed the national policy on HCWM. In seizing this opportunity, the elemental thinking must change from a linear model to the complex adaptive model that takes account of the inter-relationships and contextual factors that could impede or facilitate implementation of the policy. These complexities account for the ‘policy-implementation gap’ associated with policy failure. This paper presents a framework that could be applied in developing, implementing, and monitoring the national HCWM policy in a lower-middle-income country. The integrative framework, identified by the acronym RADICAL, comprises the following domains in an integrated grid: Raise awareness; Apply formal quality improvement methods; Design for quality and safety: Involve stakeholders; Collect and Analyse pertinent data; Learn from shared experience. The pertinence of each domain to HCWM is described.

The influence of lateral pressure on ultimate strength of ship structure

ABSTRACT The lateral pressure influences the ultimate strength of double-bottom structure. In the midship section of bulk carrier, upward bottom local loads typically exceed downward loads, resulting in increased longitudinal thrust in the outer bottom plating and a reduction in the ultimate strength of the hull girder during hogging conditions. In the present research, the typical stiffened plate and double bottom structures of the Kamsarmax type bulk carrier are taken as the research objects. The nonlinear finite element method is considered to analyze the collapse behaviour of the stiffened plate and double-bottom structure under the longitudinal thrust/bending and lateral pressure, respectively. The influence of lateral pressure on buckling modes, stress distribution, collapse mode and ultimate strength is systematically demonstrated and analyzed. This research contributes significantly to the safety design of hull structures.

Exploring the multidimensional challenges in integrating Design for Safety (DfS) in the Ghanaian construction industry

Purpose The uptake of Design for Safety (DfS) practices in developing countries like Ghana has been limited. This study aims to provide an in-depth understanding of the barriers across regulatory, organizational, cultural and educational dimensions that restrict DfS assimilation in the Ghanaian construction sector. Identifying the key impediments can inform policy initiatives and industry efforts to facilitate safer construction. Design/methodology/approach A postpositive philosophy underpinned the quantitative research. Multi-stage research was used. A comprehensive questionnaire survey was designed and given to six industry experts to assess clarity, relevance and effectiveness after a thorough literature review. In all, 164 professionals were reached to take part in the study using purposive sampling and consequently snowballing. “Variables” were ranked using mean score ranking and normalization techniques; exploratory factor analysis was then used to group variables into clusters. Findings Emergent findings revealed four distinct clusters of challenges; Design Process and Communication Challenges; Regulatory and Expertise Limitations; Planning and Education Constraints; and Attitudinal and Perception Barriers. These findings help identify targeted solutions to overcome barriers including developing robust regulatory frameworks, promoting collaboration among stakeholders and cultivating a positive safety culture. Originality/value This study provides new insights into the integration of DfS in the context of the developing construction industry in Ghana. This study expands the knowledge base to drive further research in enhancing construction safety in developing countries. Practical recommendations for overcoming these challenges are proposed.