Drop Test Analysis Research Articles

Wettability and infiltration of Si drop on Si3N4 ceramic containing BaSiO3 as sintering aid

As container for the photovoltaic (PV) Si growth, fused silica crucible can only be used once owing to crystallization breakage, which inevitably reduces the quality and yield of Si. To develop re-useable crucible, Si3N4 ceramics were successfully fabricated using novel BaSiO3 (0-8 wt%) as sintering aid. Higher BaSiO3 content promotes the densification and sintering of Si3N4 ceramic. Then, the wetting/infiltration behaviors of Si/Si3N4 binary systems were systematically investigated by sessile drop test and microstructural analysis technology. With 8 wt% BaSiO3 introduction, the Si3N4 ceramic displayed larger contact angle of Si drop and excellent Si infiltration resistance, which was determined by de-oxidation rate. Moreover, three type of infiltrations, including infiltrations under Si drop and beyond Si drop (on/under substrate surface), were found and systematically analyzed. In this work, novel sintering aid (BaSiO3) was developed for Si3N4 ceramic fabrication at relatively lower sintering temperature. Additionally, the data of wetting/infiltration behavior for Si/Si3N4 binary system can be used to guide the application of Si3N4 crucible in PV Si manufacture.

Design and Analysis of a Topology-Optimized Quadcopter Drone Frame

This study focuses on the analysis and optimization of a drone frame design to enhance its performance characteristics. The design underwent drop testing, stress analysis, displacement analysis, and flow simulation to evaluate its structural integrity, deformation resistance, and aerodynamic performance. Furthermore, topology optimization techniques were employed to achieve a 30% weight reduction while maintaining the structural integrity of the drone frame. The results of the drop test analysis revealed that Design 2 exhibited lower stress levels compared to Design 1, indicating improved load distribution and structural integrity. However, Design 1 demonstrated lower displacement values, suggesting better resistance to deformation. The flow analysis indicated that Design 1 achieved lower flow velocities, indicating superior propulsion and aerodynamic performance. Through topology optimization, the mass of the drone frame was successfully reduced by 30% without compromising structural integrity. The optimized design exhibited improved stress management, reduced displacement, and slightly higher flow velocities compared to the initial design. These improvements contribute to enhanced agility, maneuverability, and energy efficiency of the drone. The findings of this study highlight the importance of considering stress distribution, displacement, and aerodynamic performance in drone design and optimization. The results provide valuable insights for the development of efficient and reliable drones.

A Comparative Study Between Conventional Concrete and Concrete Made from Plastic Waste by Using SolidWorks Software

Production of conventional concrete leads to several negative impacts on the environment while the plastic waste concrete can effectively overcome the environmental issues and having better performance than conventional concrete. Therefore, this research presents the works in producing new concrete by replacing the fine aggregates in concrete by using a mixture of soft and hard plastic waste with different ratios density. In addition, this research also aims to evaluate the mechanical and physical properties of different ratios of fine aggregate plastic waste in producing a concrete. At the end of this research, a comparison is made between the optimum composition of plastic waste concrete and conventional concrete. This study is conducted by using SolidWorks software version 2021. The tests conducted include compressive strength test, drop test, and failure analysis. The results from the compressive strength test revealed that a force at 100kN with 20% plastic waste (Sample B) showed the highest stress (18.91 MPa). Meanwhile, from the drop height of 2.0m, the impact strength of Sample B showed the highest result with a value of 7.830 x106 N/m2. However, failure analysis results revealed that Sample B has more cracking than Sample A. From the study carried out, it can be summarised that an optimum replacement of 20% plastic waste as fine aggregates in a concrete gives the best performance is the most suitable option to be used as a replacement concrete in lightweight construction.

Novel Environmentally Friendly Nanomaterials for Drag Reduction of the Emulsified Acid System.

Matrix acidizing is a technique that is widely used in the petroleum industry to remove scales and create channels in the rock. Removal of scales and creation of channels (wormhole) enhance productivity. Conventional acidizing fluids, such as hydrochloric acid (HCl) for carbonate and a mixture of hydrofluoric acid (HF) and HCl acid, are used for the matrix acidizing process. However, these fluids have some drawbacks, including strong acid strength, corrosion at high temperatures, and quick reactions with scale and particles. Emulsified acid systems (EASs) are used to address these drawbacks. EASs can create deeper and narrower wormholes by reducing the reaction rate of the acid due to the external oil phase. However, EASs have a much higher viscosity compared to conventional acidizing fluids. The high viscosity of EASs leads to a high drag that restricts pumping rates and consumes energy. This study aims to utilize environmentally friendly and widely available nanomaterials as drag-reducing agents (DRAs) of the EAS. The nanomaterials used in this study are carbon nanodots (CNDs). CNDs have unique properties and are used in diverse applications in different industries. The size of these CNDs is usually smaller than 10 nm. CNDs are characterized by their biocompatibility and chemical stability. This study investigates the use of CNDs as DRAs for EAS. Several experiments have been conducted to investigate the CNDs as a DRA for the EAS. The developed EAS was initially tested for conductivity and drop-test analysis to ensure the formation of an inverted emulsion. Thereafter, the thermal stability for the range of temperatures and the rheological properties of the EAS were evaluated to meet the criteria of field operation. Then flow experiments with EASs were conducted before and after adding the CNDs to investigate the efficacy of drag reduction of EASs. The results revealed that CNDs can be used as viscosity reducers for the EAS, where adding the CNDs to the EAS reduces the viscosity at two different HCl concentrations (15 and 20%). It reduces the viscosity of the EAS in the presence of corrosion inhibitors as well as other additives to the EAS, showing its compatibility with the field formulation. The drag reduction was observed at the range of temperatures investigated in the study. The conductivity, stability, and rheology experiments for the sample taken after the flow experiment are consistent, ensuring CNDs work as a DRA. The developed EAS with CNDs is robust in terms of field mixing procedures and thermally stable. The CNDs can be used as a DRA with EAS, which will reduce drag in pipes, increasing pumping rates and saving energy.

Development of emulsified acid system (EAS) using organoclays (OC): Rheology and implication to the acidizing

Matrix acidizing is a well-stimulation technique extensively used in the petroleum industry to increase well productivity by removing scales and creating channels in the rocks. However, conventional acidizing fluids used in this process have some limitations such as rapid reactions with scale and fines, high acid strength, and corrosion of equipment at high temperatures. To address these issues, emulsified acid system (EAS) is used in fracturing and acidizing operations for carbonate reservoirs to improve well productivity by removing formation damage. EAS can help to improve well productivity by creating deeper and narrower wormholes through reduced reaction rates of acid due to the external oil phase. However, EAS has limitations such as low stability at high temperatures, high viscosity that restricts pumping rates, potential formation damage, and difficulty in achieving homogenous mixing. Pickering emulsions, which use solid microparticles as a stabilizer instead of surfactants, show promise in overcoming these challenges due to their easy preparation, good thermal stability, and low viscosity at high shear rates.This study investigates the use of different types of organoclays (OC) for the development of an emulsified HCl acid systems for carbonate reservoirs. Several experiments were conducted to demonstrate and evaluate the use of OC for EAS and to improve field operations. To advance the development of EAS, a meticulous process was undertaken to select and optimize OCs as the key component. It include mineral characterization by XRD and XRF techniques, optimization of OC concentration (250–1000 ppm), and mixing speed (4000–8000 RPM). The thermal stability of the EAS was evaluated for a temperature range of 25–160 °C and a comprehensive analysis of EAS rheology (0.1–1000 sec−1) was performed. The conductivity, drop-test analysis, as well as micrographic analysis, were carried out to ensure the formation of invert emulsion. It was found that the required mixing speed was 6000 RPM and the optimum OC concentration was 500 ppm for developing a stable invert emulsion. The viscosity of the EAS shows increasing trends with an increase in temperature at the low shear rates (below 10 sec−1); however, at high shear rates (higher than 10 sec−1), the EAS viscosity decreases with temperature. The study found that OCs are promising emulsifiers for creating EAS with good thermal stability and low viscosity at high shear rates. The EAS formulated using OC were robust and thermally stable, making them suitable for field mixing procedures. Additionally, the OC used in the study are cost-effective, readily available, environmentally friendly, and have a high surface area, making them advantageous as an emulsifier.

Sustainable Packaging Design for Molded Expanded Polystyrene Cushion

A molded expanded polystyrene (EPS) cushion is a flexible, closed-cell foam that can be molded to fit any packing application and is effective at absorbing shock. However, the packaging waste of EPS cushions causes pollution to landfills and the environment. Despite being known to cause pollution, this sustainable packaging actually has the potential to reduce this environmental pollution because of its reusability. Therefore, the objective of this study is to identify the accurate design parameter that can be emphasized in producing a sustainable design of EPS cushion packaging. An experimental method of drop testing and design simulation analysis was conducted. The effectiveness of the design parameters was also verified. Based on the results, there are four main elements that necessitate careful consideration: rib positioning, EPS cushion thickness, package layout, and packing size. These parameter findings make a significant contribution to sustainable design, where these elements were integrated directly to reduce and reuse packaging material. Thus, it has been concluded that 48 percent of the development cost of the cushion was decreased, 25 percent of mold modification time was significantly saved, and 27 percent of carbon dioxide (CO2) reduction was identified. The findings also aided in the development of productive packaging design, in which these design elements were beneficial to reduce environmental impact. These findings had a significant impact on the manufacturing industry in terms of the economics and time of the molded expanded polystyrene packaging development.

Genome-wide identification of resistance genes and transcriptome regulation in yeast to accommodate ammonium toxicity

BackgroundAmmonium is an important raw material for biomolecules and life activities, and the toxicity of ammonium is also an important ecological and agricultural issue. Ammonium toxicity in yeast has only recently been discovered, and information on its mechanism is limited. In recent years, environmental pollution caused by nitrogen-containing wastewater has been increasing. In addition, the use of yeast in bioreactors to produce nitrogen-containing compounds has been developed. Therefore, research on resistance mechanisms that allow yeast to grow under conditions of high concentrations of ammonium has become more and more important.ResultsTo further understand the resistance mechanism of yeast to grow under high concentration of ammonium, we used NH4Cl to screen a yeast non-essential gene-deletion library. We identified 61 NH4Cl-sensitive deletion mutants from approximately 4200 mutants in the library, then 34 of them were confirmed by drop test analysis. Enrichment analysis of these 34 genes showed that biosynthesis metabolism, mitophagy, MAPK signaling, and other pathways may play important roles in NH4Cl resistance. Transcriptome analysis under NH4Cl stress revealed 451 significantly upregulated genes and 835 significantly downregulated genes. The genes are mainly enriched in: nitrogen compound metabolic process, cell wall, MAPK signaling pathway, mitophagy, and glycine, serine and threonine metabolism.ConclusionsOur results present a broad view of biological pathways involved in the response to NH4Cl stress, and thereby advance our understanding of the resistance genes and cellular transcriptional regulation under high concentration of ammonium.

Drop test analysis of ball grid array package using finite element method

Proper design of semiconductors is the most essential step in ensuring electronic product reliability during manufacturing. The adoption of design optimization approach enhances the performance and reliability of the semiconductor package, hence, minimizes product failure. Semiconductor reliability especially in the application to automobiles is very crucial. High product failure tolerance in semiconductors in automobiles is required due to problems such as defects and malfunctions that are directly linked to casualty accidents. Such high tolerance requires keen quality control up to the semiconductor solder component level. This study aims to do a sensitivity analysis of the solder balls’ material properties and its effect on the stresses experienced by the semiconductor component with respect to its reliability using drop test. A drop test analysis was simulated wherein a shorter distance of 5 mm between the package and platform was implemented to make the simulation time faster. The density and modulus of elasticity of the solder ball material were identified as the independent factors while the stresses experienced by the BGA package during the drop test is the dependent variable. The results have shown that the maximum stress for all runs was found in the same area in the package. Changing the modulus of elasticity showed greater effect on the impact stress compared to the alteration of material density.

Exploring simplification methods in reducing simulation time for drop test analysis

- Automotive electronics can produce an unprecedented level of passenger comfort and optimized performance of engine and components. However, the increasing intricacy of these electronic devices makes them more susceptible to damage due to thermal loads, mechanical drops, and engine vibrations. While physical handling of automotive components is comparatively rare, the weight and complexity of specific components such as the ECU, power module, and sensor modules, makes any drop functionally fatal. Simulation approach is considered to be essential in solving these problems by minimizing costs and effort. This paper attempts to solve the issue of mechanical drops using an explicit dynamics finite element analysis solver. Moreover, simplification methods are applied to further minimize solution costs.

High pressure buried gas pipeline leakage temperature drop testing and theory analysis

Great damages to environment will be caused once high pressure buried pipeline leakage leaks occurs. Distributed temperature sensing (DTS) is a good monitoring method of temperature change. Gas from buried pipe leaks is monitored by changes caused by the Joule-Thomson (J-T) effect. In this work, the temperature variation of buried pipeline leakage is analyzed by finite element method (FEM). The temperature drop of nitrogen at the leak hole is calculated by using the J-T empirical formula. In addition, the site test of buried high pressure nitrogen pipeline leakage is carried out. The results show that the temperature drop the leakage hole is obvious, and the temperature directly above the leakage hole decreases with the increase of the distance from the leakage hole. The larger leakage pressure, the greater the temperature drop. Therefore, the fiber needs to be placed closer to the pipeline to monitor the soil temperature change.

Elaboración y caracterización Fisicoquímica de membranas bioplásticas a base de Nopal (Opuntia ficus-indica)

The objective of the research is the physicochemical characterization of bioplastic membranes based on Nopal (Opuntia ficus-indica) to determine their possible applications. The tests performed for the characterization were: permeability, solubility, resistance, thickness, drop test and chemical analysis with the infrared spectrophotometer. Today, new and better alternatives are sought in obtaining different polymers that benefit humanity and the environment. Recycling is an option but it is not a very effective alternative for all plastics, however, biopolymers are a solution from the origin of the problem since the vast majority of them their biodegradation time is much less than that of a common plastic. Biopolymers, which for the most part come from renewable resources so they become an interesting alternative for the plastics industry. The physicochemical properties of the Nopal-based membranes (Opuntia ficus-indica), are similar to synthetic plastic membranes, being a viable alternative to replace them, thus contributing to society, with a better quality of life being environmentally friendly.

Method for Mitigating Electrochemical Migration on Printed Circuit Boards

An effective method for preventing electrochemical migration (ECM) by adding carbohydrazide as an oxygen scavenger has been investigated on FR-4 printed circuit boards with Cu or Ag comb patterns by means of water drop testing, electrochemical testing, and surface analysis. The addition of carbohydrazide increased the mean time to failure by ECM in solutions with both low and high chloride concentrations, by delaying the formation and growth of dendrites. Also, the carbohydrazide decreased the kinetics of the oxygen reduction reaction evident in polarization curves. Thus, carbohydrazide retarded the ECM phenomenon by removing oxygen from solution, which suppressed the formation of dendrites.

FE analysis of refrigerator drop test and the optimization of lower hinge geometry using equivalent static load method

To accurately predict deformations caused by an impact when a refrigerator is dropped during transport, the material model should consider the strain rates in the lower half of the refrigerator (particularly its hinges and cushions). However, dynamic finite element (FE) analysis is computationally expensive, especially when optimization schemes to minimize deformations are operated. This study reveals that, by applying the equivalent static load method, it is possible, with only one FE analysis, to obtain the load distribution that can be obtained via dynamic analysis. Based on the equivalent static load method, an optimization method is established and used to minimize hinge deformations. Comparing the results obtained by using the proposed method with the actual drop test results, we observe that the minimum hinge deformations are similar. This indicates that, by applying this FE-based optimization approach, computational costs can be reduced drastically.

Mechanical Design and Analysis of Hybrid Mobile Robot with Aerial and Terrain Locomotion Capability

Although different locomotion mechanisms are available, the use of only one locomotion system in a mobile robot restricts its application scenarios. Hybrid locomotion improves the maneuverability and flexibility of a robot. This paper introduces a hybrid locomotion mobile robot, a combination of quadruped and quadrotor system. The robot has a unique expediency to fly to remote places, then walk to perform close range operations in the field. The prime intention is to use the quadrotor to tackle large objects by flying over it. The four legs provide easy movements in uneven terrain. Thus, this robot can be used in erratic and dynamic environments where stability, maneuverability and flexibility are required. This system can be used as first responders in search and rescue missions, where it responds before human responders gets to the site and get the entire information of the area in detail (like spotting trapped ones, getting detailed 3D mapping etc.). This platform offers unique capabilities suited for search and rescue, disaster zone assistance and surveillances. This paper elucidates the mechanical design and analysis of a hybrid locomotion robot. The solid model of the robot was made using CATIA and further analysis like static analysis, computational fluid dynamics analysis and drop test analysis were performed in ANSYS.

Structural and Droptest Analysis of Helicopter Landing Skids

Structural and Droptest Analysis of Helicopter Landing Skids

Dynamic characterization of Roma Plastilina No. 1 from Drop Test and inverse analysis

Mechanical characterization of soft malleable materials represents a research challenge due to the impossibility to perform standard tests on this type of materials. Diverse characterization procedures are found in the literature for their characterization; however, little advances have been achieved at medium strain rates. This paper presents a characterization method for soft malleable materials to determine the material parameters associated with a given constitutive model. The characterization methodology posed as an inverse problem of Drop Test is formulated and solved as an optimization procedure. The input of the optimization procedure is the experimental measurement from the impact of a steel sphere, of specific diameter, freely released from a specific height on to the soft material. Specifically, the input data consist of the penetration history captured by high speed photography. The output of the procedure is the optimum set of material parameters determined by fitting a numerical simulation to the Drop Test experimental measurements. To evaluate and validate the performance of the proposed characterization method, experiments on Roma Plastilina No. 1 were conducted.

DROP TEST SIMULATION ON PEN DRIVE BY USING ANSYS

Stress is plays an important role in a structural safety of the component and integral assemblies. Structural analysis comprises the set of physical laws and mathematics required to study and predict the behavior of structures. In the present work, Drop test analysis on a pen-drive with different materials is carried out using ANSYS, to evaluate the structural safety of component, when pen-drive is falling on ground with random velocity. Developing CAD model, meshing and results are analyzed by using ANSYS. Dimensions of pen-drive are considered with respect to industrial standards. Material properties are selected as per the ASTM standard (A36). This work comes under two categories. Initially carbon steel is used for the drop test analysis. Later carbon steel is replaced by kinematic inelastic material (Plastic material) to find the structural safety of component under drop test boundary conditions. Finally results are comparing with both materials value.

An Optimization Tool for Impact Analysis of Composite Structures

Composite materials exhibit complex failure behavior under impact loading especially such as that for composite landing gear structure. Possible failure modes in composites may include matrix cracking, fiber breakage, kinking, fiber-matrix debonding or delamination between composite plies. In order to better understand the damage mechanisms and non-linear response of composite structures under impact, complex geometries, materials, ply orientations and stacking sequence need to be considered. However, general drop test analysis for composite structures usually takes a lot of computational efforts, and it may be even more expensive for failure analysis and optimization when various structural geometries and design configurations are taken into account. This paper proposes a new methodology for evaluation and optimization of failure behavior of composite structures subjected to impact loading, whereby drop test analysis of composite structures is modeled by explicitly dynamics analysis of two-dimensional structures and implicit analysis of three-dimensional solid structures to predict delamination or out-of-plane failure. The above-mentioned modeling strategy helps speed up the optimization process and considerably save computational time and efforts. The proposed methodology together with reliable optimization algorithms and failure theory criteria are integrated and coded into a FE optimization tool by Python script. It is shown that the optimization tool effectively helps engineers and researchers perform optimization of general composite structures and fully take into account of various geometries, materials, loading configurations, composite stack-up and sequences and individual ply's orientation.

Drop Test and Finite Element Analysis of Test Board

Most electronic components have high precision and expensive features and people used the drop test to determine the reliability of these electronic components effectively. This study focused on the drop test of FR-4 test board according to the JEDEC standard, to understand the test board's basic mechanical properties and variations of stress and strain on test board. This study used finite element analysis software ANSYS/LS-DYNA to perform a drop test simulation of test board under JESD22-B111 standard, with 0.5ms pulse duration time and 1500G peak acceleration as test conditions. The support excitation method was used to predict the test board response during impact. The results between full model and quarter model were compared to verify the accuracy and efficiency of finite element analysis.

Water-Soluble Ionic Palladium Complexes: Effect of Pendant Ionic Groups on Palladium Nanoparticles and Suzuki-Miyaura Reaction in Neat Water.

Three ionic nitrogen-containing chelating ligands (L1-L3) are synthesized readily through alkylation and quaternization of 2,2'-dipyridylamine. The charge distributions and natural bond orbital analyses of their cations are implemented by using density functional theory calculations. The catalytic performances of their water-soluble palladium complexes are evaluated preliminarily by using the Suzuki-Miyaura cross-coupling reaction, and high catalytic activities of aryl bromides and chlorides are achieved in neat water. The mercury drop test, poison experiments, and TEM analysis are used to demonstrate the formation of palladium nanoparticles (NPs) after the catalytic reaction. The effects of pendant ionic groups in L1-L3 on the catalytic activities and structures of the palladium NPs are disclosed. These NPs are stable in water for several weeks; they are stabilized by synergetic interactions between the chelating coordination of the 2,2'-dipyridylamino group to the surface of the palladium NPs and the electrostatic repulsion of the ionic groups in L1-L3.