Cap Design Research Articles

Experimental measurement and modeling of the internal pressure in cylindrical lithium-ion battery cells under abuse conditions

The internal pressure evolution of cylindrical lithium-ion battery cells under abuse tests is evaluated in this work. The pressure evolution is recorded through a cavity at the center of the inner structure of the cylindrical cell. Understanding pressure buildup due to exothermic reactions aids in designing safety features, such as improved venting mechanisms. The pressure activation for the safety mechanism depends on both the venting cap design and the different abuse test conditions. This study focuses on two important parameters: the state of charge (SOC) and the overheating ramp. The SOC significantly influences the venting pressure activation at the overheating abuse tests. The 18650 cell exhibits a similar venting behavior as the 21700 cell, with pressure safety mechanisms activating sooner for the 18650 cell. The geometric structure of the battery and safety mechanisms significantly influence vent-activation thresholds. After the Current Interruptor Device (CID) breakdown, pressure rises exponentially until venting occurs, due to gas generation from the decomposition of internal components and electrolyte vaporization. With the experimental data for the overheating abuse test, a model that predicts the evolution of the pressure has been developed. For the overcharging abuse test, the pressure evolution has been measured with different current rates (C-rates) to simulate overcharge with standard charging current and fast charging current. However, the internal pressure inside the cell activates the current interrupt device, which avoids overcharging the cell, thus preventing the thermal runaway (TR) from occurring.

Optimizing Sheet Metal Formation through Advanced Hydroforming Simulation Technique

In this study, we investigate into the simulation of sheet metal hydroforming for crafting the cap of the axle-hub of a tip trailer within our manufacturing facility. This cap serves a crucial role in safeguarding wheel bearings from the detrimental effects of dust, sand, and dirt. The motivation for this work arises from the challenges encountered during the fixation of a conventional dust cap, which often falls off when subjected to pressure or threading, particularly when the tractor is in motion. The innovative approach pursued in this research involves the utilization of lightweight aluminum sheet metal for cap production, owing to its facile formability. The cap design incorporates four evenly distributed holes around its circumference and secures to the flange using screws. Prior to the manufacturing phase, a simulation of the cap-forming process was conducted using ANSYS Model 15, a computer-aided engineering program. The necessary models were crafted in CATIA, a computer-aided design program, streamlining the entire process to enhance efficiency, reduce costs, and minimize manpower requirements. The simulation encompassed three different thicknesses (1 mm, 2 mm, and 3 mm) for two distinct aluminum alloys, namely 1100 and 5652. The objective was to discern the optimal alloy for the forming process. Essential mechanical properties, including ultimate tensile strength, modulus of elasticity, and yield stress, were input into the ANSYS program to accurately reflect the materials' behavior during forming. The outcomes of our investigation revealed that aluminum alloy 5652 outperformed 1100 in terms of formability. The former exhibited a forming pressure of 300.2 MPa, while the latter required 298.3 MPa for the same forming depth (40 mm) across all three thickness variations. Additionally, the study demonstrated that 5652 is not only more efficient but also safer and more resilient than 1100.

Design and Optimization of LPG Safety Cap using Finite Element Method

This paper presents a comprehensive study on the design and optimization of LPG safety caps, aimed at enhancing safety, reducing material consumption, and optimizing performance. The project employs SolidWorks simulation tools to conduct research and concept design phases. The primary objective is to ensure product safety while minimizing costs through Finite Element Analysis (FEA). The final product undergoes rigorous evaluation for performance and consumer safety. Three main goals guide this investigation: to scrutinize existing LPG safety cap designs, minimize material usage, and simulate the optimal design for enhanced safety. Analysis of the current design reveals vulnerabilities, including theft of LPG gas from sealed cylinders and escalating HDPE prices. Proposed designs simplify the current model and economize material consumption, successfully addressing the second objective. Through simulation, an optimal design (Design 8) emerges with superior characteristics compared to the existing model. Design 8 demonstrates a reduced total weight, higher safety factor, and lower maximum von Mises stress value. Notably, it exhibits enhanced safety and resilience, mitigating failure risks under stress conditions. The findings highlight the potential for creating stronger and safer designs while minimizing material requirements. In conclusion, Design 8 emerges as a superior alternative to the current design, boasting advantages in weight reduction, stress tolerance, safety factor, and optimization potential. This study underscores the significance of utilizing advanced computational methods to refine engineering designs for improved safety and efficiency in LPG safety caps.

Advances and applications of the strut-and-tie method in reinforced concrete design: A state-of-the-art review

The Strut-and-Tie Method (STM) is a versatile and powerful approach widely used in the design and analysis of reinforced concrete structures, particularly in regions with complex stress distributions and discontinuities. This review article delves into the theoretical foundations, practical applications, and experimental validations of the STM. The article begins by exploring the fundamental principles of the STM and its historical development, with a focus on its application in predicting the capacity of reinforced concrete members. Additionally, the STM efficacy in designing deep beams and comparisons with other analytical methods are thoroughly examined. Notably, the review includes a discussion on the application of STM in concrete beams, highlighting its ability to accurately predict capacity. Several studies investigating the behavior of reinforced concrete deep beams with openings, shear-strengthened deep beams, and continuous deep beams using the STM approach are critically analyzed, providing valuable insights into its reliability and practicality. Furthermore, the review delves into advancements in computational tools and finite element analyses that have been integrated with the STM, offering a more comprehensive and robust approach to design and analysis. The article also evaluates practical applications of STM in engineering scenarios, such as the design of bridge pier caps and complex regions, showcasing its versatility and adaptability. In conclusion, this review underscores the pivotal role of the Strut-and-Tie Method in modern reinforced concrete design and analysis. It serves as a valuable resource for engineers, researchers, and practitioners seeking to apply this method effectively in various structural configurations and challenging scenarios. Ultimately, the article emphasizes the significance of STM as a reliable and efficient tool for optimizing the design and ensuring the safety and performance of reinforced concrete structures.

Numerical investigation of in-cylinder gas motion dynamics in a heavy-duty direct injection hydrogen internal combustion engine

Mixture homogenization is one of the most important parameter for hydrogen internal combustion engines (H2ICE) to achieve near-zero NOx emissions and stable combustion, especially when premixed combustion strategy is used. On the other hand, inhomogeneities are inevitable due to the limited duration for mixing. This is more prominent in H2ICEs; those adopts low pressure direct injection (LPDI) system. Optimizing an engine to achieve higher level of homogeneity requires profound understanding of in-cylinder gas motion and mixing dynamics.To establish deeper comprehension of gas motion inside the cylinder, a 13-L LPDI H2ICE was modelled, and effect of different parameters were investigated by a holistic 1D-3D simulation methodology. While boundary conditions of operating point were obtained from the 1D simulations, different swirl numbers (SN), piston shapes and injector cap designs were simulated with 3D-CFD. Simulation results were analyzed based on uniquely defined parameters like homogeneity index (HI) and symmetricity of motion (SOM), as well as standard parameters like turbulence kinetic energy (TKE), and 3D visualizations of equivalence ratio iso-surfaces. Analysis showed that, there is a negative correlation between SN and HI under investigated conditions. Moreover, it was found that piston shapes which are promoting the tumble motion, improved average TKE by 31% and HI by 28% over base piston. This study aims to be a reference for the in-cylinder gas motion design of ultra-lean LPDI H2ICEs, where the target is retrofitting an existing diesel engine and attaining the best HI, SOM and TKE values at rated power conditions.

On the design of price caps as sanctions

A ceiling has been imposed on the price at which Russian producers can sell oil. The price cap is intended to reduce Russian government tax revenue without increasing the world price of oil excessively. We show that such price caps can have counterintuitive effects. A price cap can induce sanctioned producers to increase their output, thereby increasing their revenue. This increased output can also reduce the world price of the homogeneous product supplied by sanctioned and non-sanctioned producers. The welfare-maximizing price cap, which is often well below the unrestricted world price, can increase welfare substantially.

Creating anatomically-derived, standardized, customizable, and three-dimensional printable head caps for functional neuroimaging.

Consistent and accurate probe placement is a crucial step towards enhancing the reproducibility of longitudinal and group-based functional neuroimaging studies. While the selection of headgear is central to these efforts, there does not currently exist a standardized design that can accommodate diverse probe configurations and experimental procedures. We aim to provide the community with an open-source software pipeline for conveniently creating low-cost, 3-D printable neuroimaging head caps with anatomically significant landmarks integrated into the structure of the cap. We utilize our advanced 3-D head mesh generation toolbox and 10-20 head landmark calculations to quickly convert a subject's anatomical scan or an atlas into a 3-D printable head cap model. The 3-D modeling environment of the open-source Blender platform permits advanced mesh processing features to customize the cap. The design process is streamlined into a Blender add-on named "NeuroCaptain". Using the intuitive user interface, we create various head cap models using brain atlases, and share those with the community. The resulting mesh-based head cap designs are readily 3-D printable using off-the-shelf printers and filaments while accurately preserving the head topology and landmarks. The methods developed in this work result in a widely accessible tool for community members to design, customize and fabricate caps that incorporate anatomically derived landmarks. This not only permits personalized head cap designs to achieve improved accuracy, but also offers an open platform for the community to propose standardizable head caps to facilitate multi-centered data collection and sharing.

Characterization of pristine and aged NMC lithium-ion battery thermal runaway using ARC experiments coupled with optical techniques

Battery thermal runaway (TR) challenges battery applications due to safety considerations, potentially endangering consumers. Understanding the process is crucial to defining first alarm strategies that indicate the risk of TR and designing systems to mitigate this problem. For this reason, the present paper aims to characterise key variables of the venting and thermal runaway processes. Experimental tests were conducted in an accelerating rate calorimeter (ARC) using the heat wait seek (HWS) protocol, which tracks the battery temperature after detecting an exothermic reaction during the seek period. The maximum temperature rise rate and peak temperature that the calorimeter can achieve are 15 °C/min and 300 °C. Two optical accesses in the ARC were modified to use optical techniques such as Schlieren double pass and infrared. The results cover 3 different cell conditions: Pristine cells at state of charge (SOC) 100 %, pristine cells at SOC 50 %, and aged cells at SOC 100 %. For statical purposes, each cell condition was repeated 5 times. The aged battery was cycled to boost solid electrolyte interface growth. The images obtained were post-processed, with a specific methodology for each optical technique, and according to the parameters intended to be obtained. The main result shows that for higher SOC, the exothermic reaction is detected earlier than for SOC 50 %, which was only detected in an advanced TR stage (higher temperature rise rate). Therefore, the battery system capability to detect plays a crucial role in safety. Safety actuation time is reduced by ∼ 40 % for SOC 50 %. However, the energy to manage during this situation is lower (∼42 %), depending on the mass inside the battery, revealing the importance of a good venting cap design. Infrared images have shown higher particle temperatures for higher SOC, about 150 °C higher than the SOC 50 %. The particle velocity, in this case, achieved 30 m/s.

Prefilled Ophthalmic syringes - New Possibilities in Terminal Sterilization.

In a joint study carried out by Gerresheimer, Sterigenics and Früh, it could be shown that also NO2 is well suited to terminally sterilize prefilled ophthalmic syringes. In detail 5 topics were addressed: (1) Compare EtO vs. NO2 penetration into the filled syringe; (2) Analyze gas ingress though 4 different plunger stoppers including silicone oil free and standard rubber plungers; (3) Scrutinize gas ingress through 2 different cap designs based on different elastomer properties; (4) Investigate gas permeation through COP plastic barrels compared to glass; (5) Check if the Tyvek®-layer has an influence on either sterilization.Depending on the needs a suitable sterilization method, packaging and syringe type can be suggested to customers.

Landfill cap models under simulated climate change precipitation: assessing long-term infiltration using the HELP model

The Hydrologic Evaluation of Landfill Performance (HELP) model (v 3.04) was used to assess the hydrological performance of two large-scale (~ 80 × 80 × 90 cm) laboratory-based landfill cap models. Desiccation cracking under simulated climate change precipitation (CCP) events was modelled to predict the performance of landfill caps over a 50-year period in Cumbria England, UK. Cumulative infiltration values under different climate conditions were highly sensitive to macro-pore development in the clay liner which is represented by the changing hydraulic conductivity in HELP simulations. Simulation results of cap design 1 (a clay barrier layer only) show that cumulative annual infiltration under normal precipitation (NP) and CCP events, with the initial hydraulic conductivity, ranged between 1 and 2% of the annual precipitation; however, cumulative annual infiltration was 10 to 68% when maximum (degraded) hydraulic conductivity values were used in simulations. A geosynthetic clay liner (GCL) included in cap design 2 significantly reduce cumulative infiltration.

Co-designing for the NHS: the development of sustainable theatre garments

AbstractNHS Scotland, one of the keystone healthcare providers in the UK, have recently set a wide variety of sustainability targets in an effort to mitigate waste and the intensive energy demands of healthcare. Medical garment production, management and design is an area in which design researchers can explore and offer solutions. This paper presents a series of co-design explorations to examine design alternatives to single-use theatre caps, the majority of which are currently disposed of routinely. Using a series of probes, major insights into how theatre cap design may be improved is presented.

Optimum design of pile cap considering minimization of environmental impacts

Optimum design of pile cap considering minimization of environmental impacts

Evaluation of Pile Cap Reinforcement Design Using Conventional and Finite Element with Strut and The Method Based on SNI 2847-2019

The Strut and Tie Method (STM) is one effective method for predicting the ultimate strength, failure modes, and behavior of reinforced concrete pile caps. However, the use of the strut and tie method in pile cap design in Indonesia is not as popular as the use of conventional methods. This study aims to evaluate the reinforcement design of pile caps using conventional methods and the finite element method (FEM) approach, utilizing the strut and tie method specified in SNI 2847 2019. The analysis results show that the required area of longitudinal reinforcement in the conventional method does not meet the criteria when evaluated using the STM method. The deficiency in the longitudinal reinforcement area amounts to 40.13% compared to the design results obtained using the STM method. Meanwhile, the use of the FEM method results in a required reinforcement area that exceeds the required area for the STM method. The difference in reinforcement is even greater, reaching up to 7.85% for the FEM method.

Mitigating air and noise pollution through highway capping: The Bundang-Suseo Highway Cap Project case study

Highways, while vital for transportation, often lead to heightened air and noise pollution, adversely affecting nearby communities. This study delves into the effectiveness of highway capping, a sustainable urban development strategy, in addressing these environmental challenges, with a specific focus on the Bundang-Suseo Highway in South Korea. This study employed a multifaceted approach, incorporating on-road monitoring, in situ measurements, and vertical assessments using UAVs. Following the cap's installation, the area experienced more stable pollutant levels, marking a notable shift from the previously fluctuating conditions heavily influenced by the highway. In-depth in situ monitoring near the cap revealed significant reductions in noise and pollutants like UFP and BC. Furthermore, UAV monitoring captured these changes in pollutant levels at different altitudes. Notably, the installation of the highway cap led to increased PM2.5, PM10, and NO2 levels at ground level, but a decrease above the cap, emphasizing the critical importance of intentional highway cap design in enhancing urban air quality and reducing exposure to harmful pollutants. This research yields invaluable insights for urban planners, health authorities, and policymakers, aiding the precise identification of pollution-prone areas and advocating for improved highway cap design to enhance urban environments.

Buckling behaviour of steel dome cap design under external pressure

This study aims to numerically investigate the buckling behaviour of externally pressurised dome caps. Following the recommendations of the European Standard EN 1993-1-6, there was good agreement between the Finite Element (FE) model and the experimental results, with an average difference of less than 7 %. Several imperfection approaches, such as (i) single load indentation (SLI) and (ii) axisymmetric outward bulge (AOB), and (iii) eigenmode-affine (EM) were used to analyse the dome cap. The EM proved to be the worst imperfection for the externally pressurised dome cap, yet the SLI is an attractive technique for simulating realistic imperfections. The imperfection tolerance was designed according to EN 1993-1-6, and the SLI was used for the realistic-case imperfection. From parametric study, a plot of the upper and lower bound curves serves as a design recommendation, similar to the NASA SP-8032 guideline. Through a regression analysis, a first-cut estimation equation of the imperfect dome cap buckling load with reliability of R2 = 0.97. A case study of shell buckling design on pressurization damage to an oil storage tank's spherical shell partition and its stress assessment are evaluated. This study provides a practical solution for the evaluation of buckling of steel domes under external pressure.

Probabilistic analysis of georisk from capping of contaminated sediment in Gunneklev Fjord, Norway

The seabed of the Gunneklev Fjord in south-eastern Norway is covered with exceptionally soft contaminated sediment containing mercury and dioxins. The sediments have an undrained shear strength less than 1 kPa and a variable thickness of up to 2.5 m. To reduce the potential for leaching of contaminants from these sediments, Hydro Energy AS developed a remediation plan involving capping of the sediment. Significant uncertainties are associated with the sediment's undrained shear strength and the cap thickness. An unfortunate combination of low shear strength and thick cap could cause slope failure (e.g. translational sliding of the sediment and/or bearing capacity failure (e.g. punching through). Failure, particularly slope failure, can cause spreading of the contaminants in the fjord causing serious consequences. This paper presents an assessment of the probability of slope failure associated with the contaminated sediment before and after the cap placement. Probability of bearing capacity failure is considered to have more local effect and is also discussed briefly. The study used the Monte Carlo method with random undrained shear strength and sediment thickness. The simulations show high slope failure probability when the seabed inclination was ≥ 1:50 combined with an average undrained shear strength ≤ 0.4 kPa. Based on the probabilistic analyses, a pilot field testing campaign was carried out (after this study) with 20-cm thickness cap in the “gentle” sloping area and 5-cm thickness in the “steep” areas to avoid causing a failure. The analyses were used to support evidence-based decision-making on the cap design and implementation for further field testing.

Design of Special Equipment for the Mechanical Testing of Runway Light Fixtures

Runway lights are essential components of the airstrip. However, there is currently no international standard that outlines methods for the testing of runway light fixtures. In this study, a novel testing method is developed to simulate the forces exerted on the lights during landing. The testing equipment is specifically designed to be easily mounted on a standard hydraulic press commonly used for tensile tests. This system allows for the regulation of the normal force between the aircraft tire and the fixture of the runway lighting system. To minimize load fluctuations during part sliding, Belleville washers are employed. The overall compliance of the system is validated through finite element analysis. Tests carried out by means of the proposed testing equipment allow the effective description of the variations in load at different positions during sliding. The system presented in this paper can be used to investigate the effects of landing on various combinations of cap design and tire material.

In vivo corneal confocal microscopy: Technical innovations and frontier applications

At present, the only commercially available system for in vivo Corneal Confocal Microscopy enables unique insights into the corneal morphology, especially corneal nerves. Unfortunately—technology, user‐friendliness and image analysis of the standard platform has remained at the level of 15 years ago. This contribution presents cutting edge insights into new developments based on research within our German Research Foundation supported interdisciplinary research network. This covers a wide range of new developments addressing usability, large field as well as 3D imaging, dedicated contact cap designs, elastic image registration and AI based tissue classification. Furthermore, cutting edge technologies offer 4D imaging to perform dynamic investigations and multiwavelength as well as OCT‐guided Corneal Confocal Microscopy. Finally, key aspects demonstrating the potential of the technique for static and dynamic corneal nerves analysis will be presented.

Design and application of the medical ice cap with bi-directional opening

Design and application of the medical ice cap with bi-directional opening

An Eco-Innovative Green Design Method using the Theory of Inventive Problem Solving and Importance–Performance Analysis Tools—A Case Study of Marker Pen Manufacturing

This study explores innovative designs for the cap of a marker pen, aiming to address the issues of cap loss and ink evaporation during marker pen usage. This study applies intrinsic safety, universal design and TRIZ as research methods. TRIZ has great potential to address most of the Sustainable Development Goals (SDGs) relevant to conflict-oriented problem solving for innovations. The principles of simplification, foolproof design, clarity of states, and tolerance from intrinsic safety were applied to prevent cap loss and minimize the risks associated with ink evaporation. The TRIZ methodology’s contradiction matrix was utilized to identify relevant inventive principles by improving parameters and avoiding worsening parameters, providing a reference basis for product structure design. Lastly, the principles of equitable use, simplicity, intuitiveness, and effortless design from universal design were employed to enhance the marker pen’s usability for the general public. This study creates a SERVQUAL questionnaire to compare the prototype of the designed pen cap with commercially available pen caps. It utilizes the two-dimensional quality model (Kano model) and Importance–Performance Analysis (IPA) for practical design analysis. Finally, the prototype structure is visualized using graphic software. The innovative design features of this study include the following. (1) Concealable pen tip: the sliding seal hides the pen tip inside the pen body when the pen core is slid upwards, preventing cap loss and ink drying. (2) Quick retractable function: using a pressing mechanism, the pen tip can be quickly retracted with a one-handed press and slide motion. (3) Replaceable pen core: the pen core can be replaced by disassembling the pen body, removing the old pen core, and inserting a new one, thereby extending the pen’s lifespan. (4) Satisfaction evaluation of the innovative pen cap design: through questionnaire surveys and cross-analysis using the IPA and the Kano model, this study assesses the product’s manufacturing and mass production value to reduce actual product development costs and time.