scholarly journals RESULTS OF STATIC TESTS OF PROTECTIVE STRUCTURES OF AGRICULTURAL TRACTORS CABINS

2021 ◽  
Author(s):  
S. Postelga ◽  
Keyword(s):  
Extreme Point ◽  
Free Space ◽  
Control Point ◽  
Applied Force ◽  
Protective Structure ◽  
Compression Tests ◽  
Lateral Direction ◽  
Static Tests ◽  
Displacement Sensors ◽  
Applied Forces

The purpose of research is determination of cabin deformation indicators using standardized methods and developed technical means. Research methods. The tests were performed according to the methods described in [DSTU ISO 5700, 2019] using a loading bench, pressure and displacement sensors, digital measuring amplifier Spider 8 and laptop Panasonic CF-19 Touchbook, model: CF-19KHR88PE. Research results. The protective structure AI.209.45.011.00 of the cab of tractors type C25 "Slobozhanets" was provided for testing. Before the tests, the dimensions of the cab structure were measured and recorded. During the first longitudinal loading from front to right, the load was applied to the upper transverse element of the protective structure. The point of application of the load was at a distance of 260 mm from the outer corner of the edge of the protective structure. An even load distribution in the direction perpendicular to the direction of action and along the loading beam was ensured using a sealing element. The value of the energy absorbed by the protective structure was 13100 J (required energy - 12586 J) with a maximum applied force of 82 kN and a displacement of 340 mm. During the first and second compression tests, the structure was loaded vertically with a force of 180 kN along the front and rear upper transverse elements of the protective structure with a holding of the specified force for 5 s. The side load was applied horizontally to the upper right longitudinal element of the protective structure at a distance of 85 mm forward from the control point of the driver's seat. The length of the loading beam was 600 mm. The value of the energy absorbed by the protective structure of 17000 J (required energy - 15732 J) at a maximum applied force of 80 kN and a displacement of 290 mm was achieved. After all test stages, the frontmost point of the protective structure was 70 mm and the front left point was 35 mm. The rear end points were also shifted backwards by 45 mm - right and 30 mm - left. In the lateral direction, the front right extreme point moved forward by 15 mm. After the tests, the free space area was not violated. Conclusions. The methods and technical means used during the tests allow determine the magnitude of the applied forces and deformation with the necessary accuracy and reliability. During the compression tests, the values of the test force (180 kN) were achieved, and during the application of horizontal loads - the energy absorbed by the protective structure (13100 J - longitudinal load and 17000 J - lateral load). The greatest final deformation was suffered by the protective structure at the front extreme point - 70 mm, while the violation of the zone of free space of the driver by the elements of the protective structure is not observed. Therefore, the protective structure AI.209.45.011.00 cab of tractors type C25 "Slobozhanets" withstood static tests for compliance with DSTU ISO 5700.

Impact action of a projectiles on special protective structures and ways to increase their protective capacity

2021 ◽  
pp. 95-100
Author(s):  
A. Andrukhiv ◽  
A. Baranov ◽  
N. Huzyk ◽  
B. Sokil ◽  
M. Sokil
Keyword(s):  
Soil Layer ◽  
Strength Characteristics ◽  
Protective Structure ◽  
Impact Action ◽  
Dirac Delta ◽  
Wood Flooring ◽  
Protective Element ◽  
Applied Forces ◽  
Protective Structures ◽  
Elastic Elements

A method for studying the reaction of elastic elements of protective structures to a series of impact actions of shells has been developed. In the work, the elastic elements of the protective structure are modeled by homogeneous beams, and the dynamic action of the shells is simulated by instantaneous point-applied forces. A mathematical model of this dynamic process is constructed, which is a boundary value problem for a hyperbolic equation with an irregular right-hand side. The latter is described using Dirac delta functions. Cases of both fixed and free ends of protective elements are considered. The main ideas of perturbation methods are used for the researches carried out in the work. Analytical dependences for the description of elastic deformations of a protective element which are basic for definition of its strength characteristics are received. They and the graphical dependences built on their basis for specific cases show that the dynamic deformations of the protective element for the fixed ends are greater in the case of the projectile closer to its middle, at the same time for the free ends – closer to the end. With regard to the modernization of protective structures, the dynamic effect on their elements can be reduced by using elastic reinforcement or changing the method of fixing the ends of the protective element: elastic or with a certain angle of inclination of the bearing surfaces. It is proposed to use special plastics, soil layer, flexible wood flooring, etc. as elastic reinforcement. The technique used in the work is the basis for determining the strength characteristics of protective elements, and from so – to check the reliability of the protective structure; study of the dynamics of protective and similar types of structures, taking into account the nonlinear characteristics of the elastic elements of protective structures; study of more complex oscillations of elements of protective structures. In the case of a series of impacts, it is obvious that the amplitude of deflection of the protective element after each impact will increase over time, because the model does not take into account the force of viscoelastic friction. These tasks will be the subject of further research.

Adhesion measured on the attachment pads of Tettigonia viridissima (Orthoptera, insecta)

2000 ◽  
Vol 203 (12) ◽  
pp. 1887-1895 ◽  
Author(s):  
Y. Jiao ◽  
S. Gorb ◽  
M. Scherge
Keyword(s):  
Contact Area ◽  
Silicon Surface ◽  
Compressive Force ◽  
Adhesive Force ◽  
Applied Force ◽  
Adhesive Properties ◽  
Applied Forces ◽  
Series Of Experiments ◽  
Pore Canals ◽  
Adhesive Forces

The tarsi of the cricket Tettigonia viridissima bear flexible attachment pads that are able to deform, replicating the profile of a surface to which they are apposed. This attachment system is supplemented by a secretion produced by epidermal cells and transported onto the surface of the pad through the pore canals of the pad cuticle. This study shows that the secretion alone is necessary, but not sufficient, for adhesion. To account for the full adhesive force, the deformation of the pad and the resulting changes in contact area were considered. In two series of experiments, the adhesive properties of the secretion and the adhesion of the whole pad were measured using a force tester, the sensitivity of which ranged from micronewtons to centinewtons. The adhesive forces of the secretion measured between a smooth sapphire ball with a diameter of 1.47 mm and a flat silicon surface ranged from 0.1 to 0.6 mN. In a control experiment on the silicon surface without secretion, no adhesive force was measured. There was no dependence of the adhesive force on the applied compressive force. When an intact pad was pulled off a flat silicon surface, the adhesive force increased with increasing applied compressive force, but it did not increase further once the applied force exceeded a certain value. The saturated adhesive force, ranging from 0.7 to 1.2 mN, was obtained at applied forces of 0.7-1.5 mN. The hemispherical surface of the pad had a larger contact area and demonstrated greater adhesion under a larger applied force. Adhesion became saturated when a pad was deformed such that contact area was maximal. The tenacity (the adhesive force per unit area) was 1.7-2.2 mN mm(−)(2).

Experimental investigation of the quasi-static and impact tests on the energy absorption characteristics of coupler rubber buffers used in railway vehicles

2018 ◽  
Vol 233 (9) ◽  
pp. 937-950 ◽  
Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
High Speed ◽  
Compression Tests ◽  
Static Compression ◽  
Static Tests ◽  
Impact Tests ◽  
High Speed Trains ◽  
The Impact ◽  
Absorption Characteristics

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.

scholarly journals Investigation of Biomechanical Characteristics of Orthopedic Implants for Tibial Plateau Fractures by Means of Deep Learning and Support Vector Machine Classification

2020 ◽  
Vol 10 (14) ◽  
pp. 4697 ◽  
Author(s):  
Bogdan Niculescu ◽  
Cosmin Ioan Faur ◽  
Tiberiu Tataru ◽  
Bogdan Marian Diaconu ◽  
Mihai Cruceru
Keyword(s):  
Support Vector Machine ◽  
Tibial Plateau ◽  
Orthopedic Implants ◽  
Tibial Plateau Fractures ◽  
Applied Force ◽  
The Other ◽  
Support Vector ◽  
Svm Classifier ◽  
Significant Difference ◽  
Applied Forces

An experimental comparative study of the biomechanical behavior of commonly used orthopedic implants for tibial plateau fractures was carried out. An artificial bone model Synbone1110 was used and a Schatzker V type tibial plateau fracture was created in vitro, then stabilized with three different implant types, classic L plate, Locking Plate System (PLS), and Hybrid External Fixator (HEF). The stiffness of the bone—implant assembly was assessed by means of mechanical testing using an automated testing machine. It was found that the classic L plate type internal implant has a significantly higher value of deformation then the other two implant types. In case of the other implant types, PLS had a better performance than HEF at low and medium values of the applied force. At high values of the applied forces, the difference between deformation values of the two types became gradually smaller. An Artificial Neural Network model was developed to predict the implant deformation as a function of the applied force and implant device type. To establish if a clear-cut distinction exists between mechanical performance of PLS and HEF, a Support Vector Machine classifier was employed. At high values of the applied force, the Support Vector Machine (SVM) classifier predicts that no statistically significant difference exists between the performance of PLS and HEF.

Experimental study of corrugated tubes under lateral loading

2012 ◽  
Vol 226 (2) ◽  
pp. 109-118 ◽  
Author(s):  
A Eyvazian ◽  
I Akbarzadeh ◽  
M Shakeri
Keyword(s):  
Experimental Study ◽  
Energy Absorption ◽  
Lateral Loading ◽  
Lateral Direction ◽  
Static Tests ◽  
Crushing Force ◽  
Innovative Solution ◽  
Thin Walled ◽  
Energy Absorbers ◽  
Absorption Characteristics

Thin-walled tubes are widely used as energy absorbers in various vehicles and moving parts. The objective of this study is to investigate the energy absorption characteristics of tubes with corrugations in different geometries, under lateral loading. In order to produce corrugations, an innovative solution is introduced. Quasi-static tests were conducted to study the effect of changing the corrugation geometry (type and amplitude). The results show that tubes with corrugations have a higher mean crushing force which is directly proportional to the number of corrugations and their amplitudes. Moreover, it was observed that corrugated tubes can absorb approximately four times more energy than the tubes without corrugations in the same sizes and weights. Finally, it was found that corrugated tubes are more effective in lateral direction as energy absorbers, as they present suitable force–deflection responses.

Impact Compressive Fracture of Synthetic Quartz Accompanied by Electromagnetic Phenomenon

2016 ◽  
Vol 715 ◽  
pp. 13-20
Author(s):  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Kenichi Tanigaki ◽  
Kinya Ogawa
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Waves ◽  
Dynamic Compression ◽  
Compression Tests ◽  
Ferrite Core ◽  
Static Tests ◽  
Synthetic Quartz ◽  
Loading Direction ◽  
Electromagnetic Phenomenon ◽  
The Relationship

In order to clarify the relationship between the mechanical properties of synthetic quartz and the electromagnetic phenomena during its fracture, a series of uniaxial compression tests were carried out at quasi-static and dynamic rates. Not only the stress-strain curves but also the output of ferrite-core antenna located close to the specimens were measured in a shield box made of permalloy plates. Since the synthetic quartz has three characteristic axes, i.e. optical axis, electric axis and machine axis, the effect of loading direction on the mechanical properties and electromagnetic phenomena of quarts was also examined. The dynamic compressive strength was greater than those in static tests and there is strain-rate dependence in their strength of synthetic quartz. It was also found that there are not any remarkable differences due to the loading direction with respect to the intensity of electromagnetic waves measured in the dynamic compression tests, i.e. the electromagnetic phenomenon does not depend on the loading direction.

scholarly journals Tingkat Kepuasan Parkir Kampus Anggrek Binus University Ditinjau dari Fasilitas Geometri dan Survei Kepuasan Parkir

2013 ◽  
Vol 4 (1) ◽  
pp. 506
Author(s):  
Irpan Hidayat
Keyword(s):  
Free Space ◽  
Research Method ◽  
Satisfaction Level ◽  
Parking Space ◽  
Lateral Direction ◽  
Research Results ◽  
Geometric Conditions ◽  
Long Time ◽  
Questionnaire Form ◽  
Space Requirements

Evaluated from the level of saturation, Anggrek Campus Binus University facilities are considerably able to accommodate all vehicles to park. However, from observations over the years, even though the capacity still seems able to accommodate, there are still some drivers who have difficulty in placing their vehicle in the provided parking lots. In results, it take a long time for drivers to do the maneuvers. Due to this reason, there is a need to review the geometric conditions of a parking space and user parking satisfaction at Anggrek Campus. The research method is to conduct a survei for the parking geometry in a questionnaire form, which aims to determine the satisfaction level of the parking facility from the user side. The research results acquired for parking plot 4000 x 2400 mm, the type of vehicles that meet the requirements of free space to park in the lateral direction of the plot is city car, jeep, and MPV. As for the parking plot 5000 x 3000 mm, free parking space requirements for the lateral direction meet for all types of vehicles (city car, jeeps, MPV, sedans, and SUVs). Results stated that 39% of respondents are comfortable in terms of ease of parking, 37% of respondents express comfort in opening the car door after parking their vehicle, 24% said parking signs are very useful for them in getting the parking information. However, 22% of respondents expressed their discomfort in the ease of parking due to the geometry of 90° parking pattern.

scholarly journals The influence of uncertain loading on topology-optimized designs

2021 ◽  
Author(s):  
Philipp Hofer ◽  
Erich Wehrle
Keyword(s):  
Topology Optimization ◽  
Open Source ◽  
Large Scale ◽  
Three Dimensional ◽  
Applied Force ◽  
Structural Performance ◽  
Optimized Design ◽  
Applied Forces ◽  
Reducing Costs ◽  
The Relationship

The design of structures using topology optimization can improve the structural performance and save material, in turn reducing costs. Using a framework of large-scale, three-dimensional topology optimization implemented by the authors in an open-source multiphysical software, we investigate the influence of uncertain loading on the optimized design. Direct differentiation is used to reveal the relationship between displacements and applied force, giving an efficient and effective tool to postprocess optimized topologies. The developed methodology for the assessment of the sensitivity with respect to applied forces is explored using two three-dimensional examples: the classic MBB cantilever and a cableway pylon. The advantages and limitations of this method are discussed.

Modelling of composite materials energy by fiber bundle model

2020 ◽  
Vol 92 (1) ◽  
pp. 10401
Author(s):  
Siham Boufass ◽  
Ahmed Hader ◽  
Mohammed Tanasehte ◽  
Hicham Sbiaai ◽  
Imad Achik ◽  
...  
Keyword(s):  
Composite Materials ◽  
Fiber Bundle ◽  
Critical Force ◽  
Applied Force ◽  
Remarkable Change ◽  
Remarkable Effect ◽  
Fiber Bundle Model ◽  
Applied Forces ◽  
Fiber Breaks ◽  
Material Energy

In this paper, the fiber energy in composite materials, subject to an external constant load, is studied. The investigation is done in the framework of fiber bundle model with randomly oriented fibers. The charge transfer is done only between neighboring close fibers according to the local load sharing. During the breaking process, the fibers expand, increasing their elastic energy, but when the fiber breaks, it loses its link with its neighboring fibers reducing the cohesive energy of the materials. The results show that the material energy presents one maximal peak at cross over time which decreases linearly with the applied force and scales with the lifetime of the material. However, the temperature does not have a remarkable effect on the material energy variation. In addition, the link density fiber decreases exponentially with time. The characteristic time of the obtained profile decreases with the applied force. Moreover, this density decreases with applied forces according to the Lorentz law with a remarkable change at critical force value.

scholarly journals Small-strain deformation behaviour of a clay at frozen and unfrozen states: A comparative study

2019 ◽  
Vol 92 ◽  
pp. 04001
Author(s):  
Satoshi Nishimura ◽  
Shota Okajima ◽  
Jinyuan Wang ◽  
Bhakta Raj Joshi
Keyword(s):  
Strain Rate ◽  
Axial Strain ◽  
Deformation Behaviour ◽  
Triaxial Compression ◽  
Small Strain ◽  
Small Scale ◽  
High Plasticity ◽  
Compression Tests ◽  
Small Strains ◽  
Displacement Sensors

The small-strain deformation behaviour of frozen high-plasticity clay, and the factors influencing it were investigated through parallel tests at frozen and unfrozen states. The first and second series involved temperature-controlled triaxial compression tests on unfrozen and frozen samples, respectively, with accurate strain measurement with local displacement sensors, fully calibrated for cold environment. The small-strain loading was conducted at different axial strain rates and temperatures. At pre-yield small strains in order of 0.001%, Young's modulus was independent of the strain rate, in a same manner as in unfrozen soils. The strain rate only affected the onset of small-scale yielding and the degradation of stiffness after that. The elastic strain range was greater at lower temperature, but the degree of stress-strain non-linearity seen at small strains remained on the whole similar between frozen and unfrozen states. An interesting feature of the frozen clay's stiffness, also confirmed by third test series adopting bender elements, is that it decreases when the soil is frozen from higher effective stress. A simple model was proposed to explain this feature.

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