Support Frame Research Articles

Seismic design of variable cross-section damped steel support frame for post equipment

Seismic design of variable cross-section damped steel support frame for post equipment

Arab Websites and Sustainable Development: Framing Content and News Coverage 2024

The research aims to identify the framing of Arab news websites for sustainable development during the first half of 2024 by measuring the differences between the Egyptian Al-Ahram website and the Emirati Al-Bayan website. The research used the comparative content analysis methodology based on the framing theory. The research discovered the existence of diversity in sustainable development issues, but the Al-Ahram website gave priority to the issue of climate change, while the Al-Bayan website focused on the issue of energy. The government support frame for sustainable development dominated news coverage, and official sources constituted most of the frames in both websites. Arab websites also relied on episodic frames more than thematic frames.

Modal and dynamic stress analysis of crane support frame based on CAE technology

The support frame is the main load-bearing component of crane equipment, of which modal and dynamic stress response characteristics have a critical impact on the safety and service life of the entire mechanical structure. Based on the finite element method, the support frame model was reasonably simplified and established. By arranging REB2 elements on the contact surface of the components to be connected, the rigid connection effect of the weld was realized. Through simulation calculation and modal testing, the natural frequency and vibration mode were obtained. Through modal analysis, the dynamic response analysis model was established to determine the maximum dynamic stress variation under instantaneous loading and emergency braking conditions. The results indicate that the reliability and accuracy of the finite element analysis model are high, and the maximum deviation of natural frequencies between experimental and simulation results is less than 10 %. Besides, the performance of the support frame shows good dynamic response efficiency, which proves that the mechanical structure has high stability.

Thermal and Mechanical Fields Analysis of Superconducting Magnet and Dewar System for Double-Stator Superconducting Brushless Machines

The double-stator superconducting brushless machine (DS-SCBM) combines high torque density and excellent static sealing characteristics, as well as advantages in reliability and cost-effectiveness. To ensure the long-term stability of the superconducting magnet and Dewar (SCMD) system, this study evaluates the pressure-bearing capacity and heat leakage from the support frame, selecting appropriate materials and dimensions. Furthermore, a model of the thermal and mechanical fields for the SCMD system is developed using finite element analysis which assesses the impact of various reinforcement structures on the mechanical and thermal properties of the superconducting (SC) magnet. Based on this analysis, the dimensions of the reinforcement structures, Dewars, and vacuum interlayer are optimized. Subsequently, efforts are made to manufacture the designed system and its performance is tested.

FPGA-Based Design of a Ready-to-Use and Configurable Soft IP Core for Frame Blocking Time-Sampled Digital Speech Signals

‘Frame blocking’ or ‘Framing’ is a technique that divides a time-sampled speech or audio signal into consecutive and equi-sized short-time frames, either overlapped or non-overlapped, for analysis. The framing hardware architectures (FHA) in the literature support framing speech or audio samples of specific word size with specific frame size and frame overlap size. However, speech and audio applications often require framing signal samples of varied word sizes with varied frame sizes and frame overlap sizes. Therefore, the existing FHAs must be redesigned appropriately to keep up with the variability in word size, frame size and frame overlap size, as demanded across multiple applications. Redesigning the existing FHAs for each specific application is laborious, prompting the need for a configurable intellectual property (IP) core. The existing FHAs are inappropriate for creating configurable IP cores as they lack adaptability to accommodate variability in frame size and frame overlap size. Therefore, to address these issues, a novel FHA, adaptable to accommodate the desired variability, is proposed. Furthermore, the proposed FHA is transformed into a field-programmable gate array-based soft, ready-to-use and configurable frame blocking IP core using the Xilinx® Vivado™ tool. The resulting IP core is versatile, offering configurability for framing in numerous applications incorporating real-time digital speech and audio systems. This research article discusses the proposed FHA and frame blocking IP core in detail.

A piezoelectric driven amphibious microrobot capable of fast and controllable movement

Abstract Due to its excellent adaptability to the environment and flexibility in narrow spaces, amphibious microrobots have become an important research direction recently. This study proposes an amphibious microrobot driven by piezoelectric actuators with a body length of 4.5 cm and a mass of 1.4 g. The microrobot consists of two active front legs, two passive rear legs, two caudal fins, and a support frame. Each front leg and each caudal fin are designed as structures integrated with their respective piezoelectric actuators. The microrobot has a tilted body, and the ground exerts an oblique upward impact force that makes it jump forward when its front legs swing backwards. The opposite swing of the two caudal fins generates propulsion for swimming. The components of the microrobot are manufactured based on the monolithic laminate process. The monolithic front actuator-leg and monolithic actuator-fin both emerge from a multi-layer material laminate. The support frame is designed and fabricated as a monolithic structure to improve assembly accuracy and reduce redundant assembly steps. The manufactured microrobot demonstrates its flexible and fast amphibious movements. Its maximum land walking speed reaches 15.3 cm/s and its turning speed reaches 48.2 degrees per second. The microrobot has a maximum payload capacity of 5 g moving on land. When the front legs and caudal fins work simultaneously, its underwater swimming speed reaches 9.1 cm/s, and the maximum turning speed is 20.5 degrees per second. The microrobot also confirms a maximum payload of 3 g during its underwater movement.

Research on the Design and Bidirectional Work Process of Metal Diaphragms in Small Double-Pulse Solid Rocket Motors

According to the requirements of the small double-pulse solid rocket motor, a compartmentalized isolation device has been designed. This device consists of a metal diaphragm and a support frame. An experimental study and numerical simulation were used to verify the bidirectional working process of the metal diaphragm during operation of the double-pulse motor. The results show that the pressure-bearing capacity of the metal diaphragm meets the requirements under the working conditions of pulse I without affecting pulse II, because the metal diaphragm can provide insulation and flame retardancy. The metal diaphragm can be cracked in the direction of the preset V-groove in a relatively short time under the working conditions of pulse II, which allows the gas to flow to the first pulse combustion chamber normally. This indicates that the metal diaphragm can meet the requirements of bidirectional working process in dual-pulse motors.

Numerical model of the aortic valve prosthetic frame

Aim: To perform a quantitative analysis of the effectiveness of three concepts of heart valve prosthesis support frames from the perspective of their safety under the most critical loads, conducted through numerical modeling.Materials and Methods. The study utilized three computer-generated concepts of stent-like support frames, created based on the analysis of similar balloon-expandable prostheses. The modeling was conducted using Abaqus/CAE software and included the analysis of two key loads characteristic for this element: compression and implantation phases. A linear description of cobalt-chromium was used as the material model. The feasibility of the concepts was quantitatively assessed using von Mises stress and its qualitative distribution on the surface of the models as stress contours.Results. The analysis revealed that two of the three proposed models experienced stresses exceeding the strength limit (933 MPa) – 999.6 and 954.0 MPa during the compression phase and reaching 1022.4 and 1044.7 MPa, respectively, during the implantation phase. Concept 3 had significantly lower stresses during loading; however, in the working state, the indicators approached the threshold, reaching 924.2 MPa.Conclusion. Numerical modeling identified the inefficacy of concepts 1 and 2 and directions for optimizing concept 3 – reducing amplitudes to form a “strength reserve” for stress. The analysis emphasized the importance of numerical modeling in the early assessment and optimization of medical devices.

Design of novel bracket structure for falling film devolatilizer and numerical simulation of its film-forming property

The falling film devolatilizer is a new type of devolatilization equipment, which has the advantages of high film-forming efficiency and no mechanical transmission. In this study, a devolatilizer with an open falling film substrate was designed, and the film-forming performance and surface renewal performance of high viscosity fluids under the falling film structure were numerically simulated. The results indicate that the opening of the falling film substrate makes the liquid film thinner, which is beneficial for the stretching of the liquid film. The advantages of the falling film under low viscosity and high flow rate conditions are more significant. Simultaneously, four bracket structures were designed. Compared with the rectangular bracket, the renewal frequency of fan-shaped brackets can be increased by more than 20%, and the flow rate can be increased by about 10%. The improvement of the two can directly improve the falling film devolatilization performance, so as to improve the polymer polymerization degree and improve the product performance. Therefore, exploring the falling film support frame with high devolatilization performance provides a certain engineering practical significance for the design of devolatilization equipment.

Modal characteristics analysis of agricultural vehicle support frame

Modal characteristics analysis of agricultural vehicle support frame

Development of Modified Ride-On-Cars for Children with Mobility Impairments

Introduction: The ability to move independently is an integral part of a child's development. Children with motor impairments often experience significant challenges with moving independently, resulting in expensive powered wheelchairs being purchased or having caregivers push them in strollers or wheelchairs. The purpose of this research is to adapt motorized ride-on-cars to enable children with motor impairments to explore their environment independently. Engineers, physiotherapists, and occupational therapists co-designed customized ride-on-cars with 10 children and their caregivers to support each child’s individual needs. Methods: Physiotherapists and occupational therapists led an initial diagnostic session to assess each child’s clinical needs. The engineers then brainstormed and implemented solutions. On the final day of testing, physiotherapists and occupational therapists conducted one further clinical assessment and made final changes. This process was repeated for 10 children ages 1-3 years old who had been identified as having mobility impairment. Results: The final cars were designed to minimize cost, weight, and size while prioritizing each child’s ability to operate the car independently and safely. The main modifications included replacing the original gas pedal with an assistive switch and constructing a support frame to ensure the child’s safety. Additional modifications such as adding a steering T-bar, adding LED lights, and varying the switch location were also implemented for specific children. Each modified car was tested to ensure client safety and car durability. Client feedback was positive, and caregivers expressed how their modified car will increase mobility for their child. Conclusions: The results from this iterative co-design process emphasize the importance of team assessment and implementation when creating assistive devices. It shows that modifying standard off-the-shelf toys to the specific needs of children with disabilities can be successful and improve their quality of life.

Open-source cold and hot scientific sheet press for investigating polymer-based material properties

To produce samples for both material testing and molded sheets/parts, this article details an open-source scientific cold and hot press design. It consists of two independent and modular upper and lower plate (929 cm2) assemblies each containing four 125 W insulated steel strip heaters. The steel housing for these heaters is entirely modular and designed for ease of manufacture, assembly, and customization. This system allows a researcher with access to a hydraulic press to repurpose existing equipment into a multipurpose hot and cold press, or if an independent machine is warranted, an additional welded support frame and commercially available bottle jack offer standalone operation. By utilizing this small-scale hot press either in conjunction with a hydraulic press or on its own, samples can be produced to determine the critical material properties of any polymer, composite, or polymer blend. A series of modular molds allow for the rapid production of flat sheet stock and solid testing samples adhering to the ASTM D695 standard for rigid plastics tested in compression and ASTM D638 standard for testing plastics in tension. The sheet mold offers the user the ability to produce stock sheets that can be cut and assembled into 2.5-D applications with post processing.

Experimental and Simulation Studies on Protective Structures in Floating Dock

In this research, two distinct designs of protective structures were developed to address structural damage caused by ships impacting the internal structures of floating docks during maintenance operations. The designed protective structures consist of support sections and load-bearing sections, with the load-bearing section comprising three frame sections. For ease of description, the front frame section, middle frame section, and rear frame section are referred to as Frame A, Frame B, and Frame C, respectively. A drop-weight test was conducted with a stern-shaped indenter impacting the structures at 3.89 m/s. This study also assessed varying impact speeds and positions. The results showed that Specimen 2 had localized indentations on Frame B, while Specimen 1 exhibited overall deformation of Frame B and additional deformations in Frame A. The simulations agreed with the experimental results, confirming the model’s accuracy. At speeds from 2.34 m/s to 5.45 m/s, Specimen 2 consistently showed localized deformations, while Specimen 1 showed comprehensive deformation of Frame B at 3.89 m/s due to lower rigidity. When the indenter impacted the specimens at different locations with a speed of 5.45 m/s, the two specimens exhibited varying degrees of damage. As the impact location shifted from the central area to the end, the maximum indentation depth of Specimen 1 decreased from 52.26 mm to 41.71 mm, while that of Specimen 2 decreased from 43.26 mm to 38.50 mm. The reduction in indentation depth and extent as the impact location approached the support frame can be attributed to the increasing involvement of the web plate beneath the frame in resisting the impact. Additionally, compared to Specimen 1, Specimen 2 exhibited a relatively smaller overall indentation depth, and the impact of location variation on indentation depth was also relatively minor.

Development of a Novel Soft Tissue Measurement Device for Individualized Finite Element Modeling in Custom-Fit CPAP Mask Evaluation

PurposeIndividual facial soft tissue properties are necessary for creating individualized finite element (FE) models to evaluate medical devices such as continuous positive airway pressure (CPAP) masks. There are no standard tools available to measure facial soft tissue elastic moduli, and techniques in literature require advanced equipment or custom parts to replicate.MethodsWe propose a simple and inexpensive soft tissue measurement (STM) indenter device to estimate facial soft tissue elasticity at five sites: chin, cheek near lip, below cheekbone, cheekbone, and cheek. The STM device consists of a probe with a linear actuator and force sensor, an adjustment system for probe orientation, a head support frame, and a controller. The device was validated on six ballistics gel samples and then tested on 28 subjects. Soft tissue thickness was also collected for each subject using ultrasound.ResultsThickness and elastic modulus measurements were successfully collected for all subjects. The mean elastic modulus for each site is Ec = 53.04 ± 20.97 kPa for the chin, El = 16.33 ± 8.37 kPa for the cheek near lip, Ebc = 27.09 ± 11.38 kPa for below cheekbone, Ecb = 64.79 ± 17.12 kPa for the cheekbone, and Ech = 16.20 ± 5.09 kPa for the cheek. The thickness and elastic modulus values are in the range of previously reported values. One subject’s measured soft tissue elastic moduli and thickness were used to evaluate custom-fit CPAP mask fit in comparison to a model of that subject with arbitrary elastic moduli and thickness. The model with measured values more closely resembles in vivo leakage results.ConclusionOverall, the STM provides a first estimate of facial soft tissue elasticity and is affordable and easy to build with mostly off-the-shelf parts. These values can be used to create personalized FE models to evaluate custom-fit CPAP masks.

Design and control of a side dense transplanting machine for sweet potato seedlings on mulch film

At present, China is the leading country in sweet potato cultivation worldwide. However, there are still several problems such as high labor intensity, low efficiency of manual transplanting, and lack of machinery for side transplanting for sweet potato seedlings on mulch film. Therefore, a side dense transplanting machine for sweet potato seedlings on mulch film is designed, using a multi-row side transplanting method. It is mainly composed of a transplanting device, a seedling conveying device, a traveling device, and a control system. Based on the agronomic requirements for sweet potato transplanting, the study focuses on the structure and working principle of the complete machine. It involves the detailed structural design and motion analysis of the crank-rocker and cam of the transplanting device. Based on the sweet potato seedlings transportation plan, parameters such as the vertical height of the seedling conveying device, the size of the support frame, and the relative relationship between position of the transplanting device are determined. To ensure the smooth transplantation of sweet potato seedlings, the motor parameters required for each device are calculated and determined. An Arduino control system is developed to manage the coordinated movement of each device. Positioning components are integrated to ensure accurate coordination between the transplanting device and the seedling conveying device. This setup enables the seedling claws to pick sweet potato seedlings and perform the side transplanting on the mulch film. Field test results show the missed rate of seedlings, the qualified rate of transplanting and the qualified rate of transplanting depth are 4.13 %, 91.62 % and 93.86 % respectively. The transplant spacing coefficient of variation and the average spacing between seedlings are 1.90 and 177.06 mm respectively. All indicators of the transplanting machine meet the agronomic requirements for side dense transplanting for sweet potato seedlings on mulch film. The transplanting machine is integrated with sweet potato seedling transplanting agronomy, achieving mechanized transplanting of sweet potato seedlings, reducing labor intensity, and promoting the quality and efficiency of sweet potato production. This research provides a reference for the development of sweet potato seedlings transplanting equipment.

Bearing Steel Structures for Installation of Railway Strain Gauge Scales

Purpose. The main purpose of the publication is to compare the main technical and economic indicators of the two proposed structural variants of the support system for railway strain gauge scales for four-axle wide gauge railcars. This is due to the need to reconstruct and modernize the fixed assets of an industrial enterprise, in particular, to overhaul and replace old railway scales with modern electronic strain gauge scales. Also, the purpose of the work is related to the need to expand the range of railway cars for which the possibility of weighing is provided, including transport units of the foreign car fleet. Methodology. To achieve this goal, we analyzed the modern types of railroad cars for freight transportation, determined the main components of strain gauge scales for weighing the main types of cars, and developed a special support system to support the scale platform. The support system is provided in two design variants - with one spatial support frame and two separate flat support frames. Using the domestic design and computing complex SCAD, we built finite element models for both proposed design options. Based on the analysis of their stress-strain state, rational cross-sections were selected for each structural element, and the total mass was determined. Findings. A comparative analysis of the two developed structural solutions for the support system for modern railway strain gauges has revealed that the variant with two separate bearing frames has a lower weight by about 40 % compared to the variant with one spatial bearing frame. However, the manufacturability of its production is somewhat lower, since it involves 10 structural elements compared to 7 for variant No. 1. Originality. The numerical analysis made it possible to theoretically substantiate a more rational and efficient design solution for the support system for modern railway strain gauge scales. Practical value. A constructive variant of the steel support system has been developed and proposed for practical implementation, which is the most effective in terms of its technical and economic indicators for the existing conditions of an existing industrial enterprise. The developed design option was also coordinated with the project of major reconstruction of the building for weighing railroad cars.

Influence of Chloride Concentration on Fretting Wear Behavior of Inconel 600 Alloy.

The nickel-based alloy Inconel 600, strengthened by solution treatment, finds extensive application as a heat exchange pipe material in steam generators within nuclear power plants, owing to its exceptional resistance to high-temperature corrosion. However, fretting corrosion occurs at the contact points between the pipe and support frame due to gas-liquid flow, leading to wear damage. This study investigates the fretting wear behavior and damage mechanism of the nickel-based alloy Inconel 600 and 304 stainless steel friction pairs under point contact conditions in a water environment. Characterization was performed using laser confocal scanning microscopy and scanning electron microscopy equipped with energy-dispersive spectroscopy. Results indicate that the friction coefficient remains consistent across different chloride ion concentrations, while the wear volume increases with increasing chloride concentrations. Notably, friction coefficient oscillations are observed in the gross slip regime (GSR). Moreover, the stability of the oxide layer formed in water is compromised, diminishing its protective effect against wear. In the partial slip regime (PSR), friction coefficient oscillations are absent. An oxide layer forms within the wear scar, with significantly fewer cracks compared to those within the oxide layer in the GSR. It is worth noting that in GSR, the friction coefficient oscillates.

Effectiveness of the KiVa anti-bullying program in the Czech Republic: A cluster randomized control trial

AimsOne of the most widely used evidence-based anti-bullying programs, KiVa, originates from Finland and aims to change students’ peer context, activate teachers, and inform parents with two main components (universal preventive actions and indicated actions when bullying occurs), complemented by monitoring. Because research documented somewhat varied KiVa outcomes in different countries and because there is a lack of research focusing solely on the effectiveness of the universal and indicated actions, this study aimed to evaluate the effectiveness of KiVa main components when implemented in a new country. This two-arm parallel cluster randomized control trial (RCT) evaluated the effectiveness of the KiVa anti-bullying program in elementary schools in the Czech Republic. It examined the effects of the universal and indicated actions on self-reported bullying and victimization as primary outcomes and well-being as a secondary outcome, while keeping monitoring constant across the intervention and control schools. The study also examined the role of implementation fidelity on the proposed outcomes. MethodsSchools were allocated via stratified randomization into a KiVa intervention group (12 schools, 35 classes, N = 407 students) or a wait-list control group (12 schools, 32 classes, N = 400 students). The study employed data from baseline and post-measurement waves, which were 10 months apart. ResultsThe data were analyzed using linear mixed effects models, which showed no significant intervention or fidelity effects for bullying, victimization, and well-being. However, promising trends (at α < .10) were revealed, such as lower levels of bullying observed in the intervention group and in schools with high implementation fidelity. Additional analysis using Bayes factors supported these promising trends and provided moderate support for lower levels of victimization in the intervention group compared to the control schools. ConclusionsEvaluation of effectiveness of anti-bullying programs could benefit from a more targeted fidelity assessment at the classroom or individual level and from distinguishing between the effects of the main components of the programs and the effects of monitoring. The promising yet non-significant intervention and fidelity effects suggest that schools may require enhanced support and longer implementation time frames than a single school year, especially when implementation faces structural obstacles, such as the Covid-19 pandemic.

Experimental and simulation of a tension-like nonlinear piezoelectric energy harvester

This article proposes a low-frequency and efficient tension-like nonlinear piezoelectric energy harvester, which increases the harvesting performance of the harvester by swinging the support frame. Firstly, design the structure of the harvester and draw a physical model. Secondly, finite element models are used to simulate and analyze the structure’s dynamic characteristics. Finally, make an experimental prototype of the harvester and explore the power generation characteristics of the device through experiments. The results indicate that the harvester has two natural frequencies under low-frequency conditions. The energy harvester has the optimal external resistance to achieve peak output power. The greater the excitation acceleration, the greater the total output power value of the energy harvester. When the mass of the mass block is 3.7 g and the excitation acceleration is 0.4 g, the total output power value of the energy harvester is 3.88 mW, and the harvesting frequency band is wide, indicating excellent output performance of the harvester. The experimental results of the energy harvester device are consistent with the simulation results, fully verifying the correctness of the experiment and simulation. This piezoelectric energy harvester can efficiently harvest vibration energy at low frequencies, providing a good prospect for supplying power to microelectronic devices.

Design of Muon Campus full flow purifier for varying operational conditions and horizontal shipping

Constant ingress of impurities in Muon Campus g-2 experiment at Fermilab has resulted in reduction of efficiency of cryogenic expanders and occasional undesired downtime to flush the impurities. Due to insufficiency of current 0.06 kg/s mobile purifier, a full flow purifier is designed to be used in Muon Campus which purifies 0.24 kg/s of Helium throughput of 4 compressors through charcoal bed at 80 K and returns ambient Helium back to the system. The purifier is designed to be operated near liquid Nitrogen temperature during cold operations and up to 400 K during regeneration. Both warm and cold operational range of the purifier has required use of appropriate clearances in design due to expansion and contraction. The vessel of around 5.5 m height which is designed to be operated vertically is to be shipped horizontally. The asymmetrical position of heavy stainless steel heat exchanger in the purifier support frame and 5g vertical load design consideration for shipping has required use of shipping supports and heat exchanger rotational stops to comply with design requirements. FEA of purifier system is performed in cold, warm and shipping cases to verify that the purifier satisfies the design requirements.