scholarly journals Approaches to taking into account horizontal movements of foundations in the work of wooden reinforced cables

2020 ◽  
pp. 91-103
Author(s):  
Bohdan Demchyna ◽  
Andriy Kravz
Keyword(s):  
Experimental Tests ◽  
Metal Plate ◽  
The Body ◽  
Nonlinear Dependence ◽  
Joint Work ◽  
Reduced Cross Section ◽  
Static Tests ◽  
Steel Rope ◽  
Geometric Invariance ◽  
Ribbon Structures

The behavior of a wooden stress ribbon structures reinforced with steel rope under the action of a load evenly distributed along the entire length of the cable was investigated. The analysis of the results of static tests of the wooden reinforced cable of the VD-3.1 series is given. A criterion is proposed according to which a wooden stress ribbon structures reinforced with steel rope can be considered according to the theory of rigid threads. To ensure the stability and geometric invariance of the structures formed by rigid threads, an important role is played by taking into account the pliability of the supports that perceive the horizontal support reactions (spacing of the cable). Deformation of the supports of rigid cables causes the appearance of significant bending moments in the body of the cable, and also leads to an increase in the deflection of the structure. Therefore, special attention was paid to the study of the pliability of supports during the tests of wooden stress ribbon structures reinforced with steel rope to the action of a load evenly distributed along the length of the cable. The pliability of supports during experimental tests of wooden stress ribbon structures reinforced with steel rope was investigated. The obtained results are compared with the calculated value of the pliability of the supports, calculated based on the deformability of the installation for testing cable structures. The methods of calculating the deflections of the cables, which take into account the pliability of the supports, were tested. The influence of the pliability of the supports on the deflection of the cable is determined. At the level of the pliability of the supports, the deformability of the cable was influenced by the pliability of the nodal joints of the wooden elements of the cable. Based on this, the deformability of the joints of the wooden elements of the cable on the punched metal plate fasteners and its effect on the deflection of the cable were investigated. The coefficient of deformability of joints was suggested, which took into account the nonlinear dependence of the deformation of joints of wooden elements of the cable on the applied load. Due to the need to take into account the joint work of the wooden body of the cable and the steel rope, the calculated characteristics of the reduced cross section of the wooden cable reinforced with steel rope were calculated. A static calculation of a wooden stress ribbon structures reinforced with steel rope according to the theory of rigid threads is performed and the results of calculations are compared with experimental data.

Quality Assurance of Laser Welded Axisymmetric Sandwich Structure

2013 ◽  
Vol 549 ◽  
pp. 529-534 ◽  
Author(s):  
Kimmo Illikainen ◽  
Kalle Holappa ◽  
Kari Mäntyjärvi
Keyword(s):  
Quality Assurance ◽  
Working Conditions ◽  
Sandwich Structure ◽  
Visual Inspection ◽  
Experimental Tests ◽  
The Body ◽  
Destructive Testing ◽  
Great Strength ◽  
Static Tests

This study focuses on quality assurance in a laser welded axisymmetric sandwich structure that functions as the body of an electric machine. The manufacturing quality of the structure was measured using destructive testing and visual inspection. The destructive tests included both fatigue and static tests in addition to a macrographic examination. The visual inspection comprised ocular estimates of the laser welded seams as well as their requirements. Compared with the real working conditions of the machine, the experimental tests were exhaustive. Nevertheless, in the tests, the bodies held up very well which shows the great strength of the structure.

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

FORMATION OF EXPERIMENTAL AND METHODICAL BASIS TO ESTIMATE STRENGTH CORRESPONDENCE OF DOMESTIC PASSENGER CAR BODIES TO EUROPEAN STANDARD BASIS

2021 ◽  
Vol 2021 (8) ◽  
pp. 67-76
Author(s):  
Sergey Korshunov ◽  
Aleksandr Skachkov ◽  
Sergey Samoshkin ◽  
Aleksandr Smirnov ◽  
Dmitriy Goncharov
Keyword(s):  
International Markets ◽  
The Body ◽  
Standard Basis ◽  
Rolling Stock ◽  
European Standard ◽  
Static Tests ◽  
Railway Infrastructure ◽  
Methodical Basis ◽  
Equipment Development ◽  
European Standards

The development of the international trade and the entrance of domestic car manufacturers into international markets required bench equipment development for tests in accordance with the requirements of the European standards. In this connection the purpose of this work is to develop an experimental and methodical basis for the estimation of the strength correspondence of export railway produce to the European standard basis. In the work there is shown a description of the bench developed for static tests of rolling stock for loads corresponding to the European standard basis. In the requirements mentioned there is used a more extended list of loads and combination of efforts and the necessity in the application of longitudinal loads to the elements of the end wall in three levels should be particularly emphasized. On the test bench there are carried out static tests of the car of model 61-4514 for Egyptian national railways and the body of the motor-rail car of model 2853 for the railway infrastructure of Serbia.

scholarly journals GaIn: Human Gait Inference for Lower Limbic Prostheses for Patients Suffering from Double Trans-Femoral Amputation

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4146 ◽  
Author(s):  
Roman Chereshnev ◽  
Attila Kertész-Farkas
Keyword(s):  
Experimental Tests ◽  
The Body ◽  
Thigh Muscle ◽  
Human Gait ◽  
Portable Devices ◽  
Mobile Platforms ◽  
Biologically Inspired ◽  
Non Invasive ◽  
Standing Up ◽  
Different Parts

Several studies have analyzed human gait data obtained from inertial gyroscope and accelerometer sensors mounted on different parts of the body. In this article, we take a step further in gait analysis and provide a methodology for predicting the movements of the legs, which can be applied in prosthesis to imitate the missing part of the leg in walking. In particular, we propose a method, called GaIn, to control non-invasive, robotic, prosthetic legs. GaIn can infer the movements of both missing shanks and feet for humans suffering from double trans-femoral amputation using biologically inspired recurrent neural networks. Predictions are performed for casual walking related activities such as walking, taking stairs, and running based on thigh movement. In our experimental tests, GaIn achieved a 4.55 prediction error for shank movements on average. However, a patient’s intention to stand up and sit down cannot be inferred from thigh movements. In fact, intention causes thigh movements while the shanks and feet remain roughly still. The GaIn system can be triggered by thigh muscle activities measured with electromyography (EMG) sensors to make robotic prosthetic legs perform standing up and sitting down actions. The GaIn system has low prediction latency and is fast and computationally inexpensive to be deployed on mobile platforms and portable devices.

scholarly journals Comparative Study of Effect of Silver Nitrate Gel and Differentiated Dermal Precursors (BMSCs) on Third Degree Burn in Wistar Rats

2020 ◽  
Vol 11 (1) ◽  
pp. 200-206
Author(s):  
Balaji K ◽  
Perumal Saraswathi ◽  
Prabhu K ◽  
Shila Samuel ◽  
Melani Rajendren ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Silver Nitrate ◽  
Wistar Rats ◽  
Burn Injury ◽  
Wistar Rat ◽  
Metal Plate ◽  
Healing Time ◽  
The Body ◽  
Burn Wound ◽  
Healing Wound

Skin is an ectodermal derivative that maintains internal homeostasis of the body. Any damage to the skin like burn injury internal homeostasis is lost, resulting in delayed healing. The aim is to study the histoarchitecture comparative effect of silver nitrate gel, and BMSCs (DDP) on third-degree burns in Wistar rats. A burn wound of size 2.5 cm (length) x 2.5 cm (breadth) x 6 mm (depth) was created using a preheated metal plate on flanks of Wistar rat. Every burn wound was treated with silver nitrate gel (commercially available as silverex), bone marrow differentiated dermal precursors, and monitored for 1, 7, 14, 21 days until wound healing. Wound surface area was measured and compared among groups with histological and gross observations. The healing time was faster in bone marrow differentiated dermal precursors (DDP) group compared to control. Prolonged silver nitrate gel usage heals burn wound with no infection, but silver toxicity was noted. Wound contraction is slower but steady using bone marrow differentiated dermal precursors (DDP) cell when compared to the group treated with silver nitrate gel. The data from this study help use to use bone marrow differentiated dermal precursors (DDP) cells as an alternate and effective way to treat burn wounds.

scholarly journals Soy-enriched bread, a pilot study to determine its beneficial effects in menopause

2021 ◽  
Author(s):  
Daniela Giustarini ◽  
Comasia Ricci ◽  
Ilaria Ceccarelli ◽  
Stefano Pieretti ◽  
Paolo Andre ◽  
...  
Keyword(s):  
Experimental Tests ◽  
The Body ◽  
Many Body ◽  
Beneficial Effects ◽  
Regular Consumption ◽  
Aging Women ◽  
Before And After ◽  
Quality Of Life Index ◽  
Antioxidant Parameters ◽  
History Of

Menopause is the last step in the reproductive history of a woman. The ovaries stop producing hormones and the body reacts by lowering its functions, including the neuronal one. Phytoestrogens are plant products with estrogen-like activity able to affect many body functions. The aim of the present experiment was to study the effects of 30 days of regular consumption of a soy-enriched bread containing a known amount of phytoestrogens (genistein and daidzein). Women at climacteric, within 5 years or more than 5 years of menopause, were asked to include in their diet 200 g/day of a bread containing 40 mg of phytoestrogens. The effect on common menopausal symptoms and neurophysiological, hormonal and antioxidant parameters were determined before and after 30 days through questionnaires and experimental tests. Phytoestrogens were measured in the urine. In all groups, there was a significant increase of phytoestrogens in the urine and a decrease of the classical symptoms of menopause as well as a significant improvement in attentional performance tests, the quality of life index and pain intensity. Phytoestrogens present in the soy-enriched bread, are an important supplement in aging women due to their ability to induce estrogen-like effects without the potential side effects of estrogens.

Improving Fire Safety by Understanding the Fire Performance of Engineered Floor Systems and Providing the Fire Service with Information for Tactical Decision Making

2012 ◽  
Author(s):  
Steve Kerber ◽  
◽  
Daniel Madrzykowski ◽  
James Dalton ◽  
Bob Backstrom
Keyword(s):  
Decision Making ◽  
Multiple Scales ◽  
Fire Service ◽  
Metal Plate ◽  
The Body ◽  
Fuel Load ◽  
Firefighter Safety ◽  
Floor Systems ◽  
Floor System ◽  
The Impact

This research project was a collaboration of several research organizations, product manufacturers and fire service representatives to examine hazards associated with residential flooring systems to improve firefighter safety. Funding for this project was provided through the National Institute of Standards and Technology’s American Recovery and Reinvestment Act Grant Program. The main objective of this study was to improve firefighter safety by increasing the level of knowledge on the response of residential flooring systems to fire. Several types (or series) of experiments were conducted and analyzed to expand the body of knowledge on the impact of fire on residential flooring systems. The results of the study have been prepared to provide tactical considerations for the fire service to enable improved decision making on the fire scene. Experiments were conducted to examine several types of floor joists including, dimensional lumber, engineered I-joists, metal plate connected wood trusses, steel C-joists, castellated I-joists and hybrid trusses. Experiments were performed at multiple scales to examine single floor system joists in a laboratory up through a full floor system in an acquired structure. Applied load, ventilation, fuel load, span and protection methods were altered to provide important information about the impact of these variables to structural stability and firefighter safety. There are several tactical considerations that result from this research that firefighters can use immediately to improve their understanding, safety and decision making when sizing up a fire in a one or two family home. 
 This report summarizes the results from each of the experimental series and provides discussion and conclusions of the results. 


A shape memory alloy–actuated soft crawling robot based on adaptive differential friction and enhanced antagonistic configuration

2020 ◽  
Vol 31 (16) ◽  
pp. 1920-1934 ◽  
Author(s):  
Chen Liang ◽  
Yongquan Wang ◽  
Tao Yao ◽  
Botao Zhu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Stride Length ◽  
Parametric Design ◽  
Thermoplastic Polyurethane ◽  
Interaction Mechanism ◽  
Experimental Tests ◽  
The Body ◽  
3D Printed ◽  
Miniature Robot

This article presents a soft crawling robot prototype with a simple architecture inspired by inchworms. The robot functionally integrates the torso (body) and feet in a monolithic curved structure that only needs a single shape memory alloy coil and differential friction to actuate it. A novel foot configuration is proposed, which makes the two feet, with an anti-symmetrical friction layout, can be alternately anchored, to match the contraction–recovery sequence of the body adaptively. Based on the antagonistic configuration between the shape memory alloy actuator and the elastic body, a vertically auxiliary spring was adopted to enhance the interaction mechanism. Force and kinematic analysis was undertaken, focusing on the parametric design of the special foot configuration. A miniature robot prototype was then 3D-printed (54 mm in length and 9.77 g in weight), using tailored thermoplastic polyurethane elastomer as the body material. A series of experimental tests and evaluations were carried out to assess its performance under different conditions. The results demonstrated that under appropriate actuation conditions, the compact robot prototype could accomplish a relative speed of 0.024 BL/s (with a stride length equivalent to 27% of its body length) and bear a load over five times to its own weight.

Combined stiffness characteristic of metal rubber material under vibration loads

2019 ◽  
Vol 233 (17) ◽  
pp. 6076-6088 ◽  
Author(s):  
Hailong Fu ◽  
Zhengli Hua ◽  
Longqing Zou ◽  
Yue Wang ◽  
Jianbin Ye
Keyword(s):  
Energy Dissipation ◽  
Vibration Isolation ◽  
Influence Factors ◽  
Experimental Tests ◽  
Individual Element ◽  
Rubber Material ◽  
Static Tests ◽  
Metal Rubber ◽  
Vibration Loads ◽  
The Individual

Metal rubber is one kind of elastic cellular metal material, which is widely used in vibration isolation environment for its excellent properties of elasticity, energy dissipation, and environmental adaptability. However, the stiffness range of one single metal rubber is restricted, which limits its ability of vibration isolation, especially under the complex vibration loads. In this paper, a method of spatial overlay combination is presented to widen the range of the stiffness of metal rubber material. The contact behavior of the metal spiral rolls and the influence factors of manufacture to the stiffness are investigated according to the micro-spring theory and the energy dissipation theory. The static tests under cycling loading are conducted to obtain the average stiffness and the equivalent stiffness of the combined metal rubber. After the comparisons, the combined metal rubber has a better stiffness range than the individual element. The diameter of metal wire and the relative density of metal rubber are two important influence factors to the combined stiffness, which are verified by the experimental tests and finite element simulation.

scholarly journals Experimental tests of vehicle body accelerations at selected road and rail crossings

2019 ◽  
Vol 254 ◽  
pp. 04002 ◽  
Author(s):  
Konrad J. Waluś ◽  
Jakub Polasik ◽  
Janusz Mielniczuk ◽  
Łukasz Warguła
Keyword(s):  
Cross Section ◽  
Experimental Tests ◽  
The Body ◽  
Geometric Parameters ◽  
Vehicle Body ◽  
Delivery Vehicle ◽  
Dynamic Reaction ◽  
Level Crossing ◽  
Level Crossings ◽  
Section Structure

Vehicles moving across the railway are exposed to the dynamic reaction of unevenness of surface on those level crossing. This significantly influences on the increase of the acceleration as well as forces values transferred to the body of the car. These values depend to extent on the geometric parameters of level crossing as well as on the characteristics of the car tires and suspension. The paper presents the results of experimental tests of a small delivery vehicle crossing selected level crossings with a diversified geometric cross-section structure.

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