Aspects of a Safety Operation of Service Robots on Glass Walls

2015 ◽  
Vol 772 ◽  
pp. 461-465
Author(s):  
Marcel Horák ◽  
František Novotný ◽  
Michal Starý ◽  
Josef Černohorský
Keyword(s):  
Material Properties ◽  
Service Robots ◽  
Vacuum System ◽  
Robot Motion ◽  
High Rise ◽  
State Of Stress ◽  
Service Operation ◽  
Edge Conditions ◽  
Real Composition ◽  
Safety Operation

The paper focuses on problems of the safety operation of service robots on glass facades of high-rise buildings exposed to a local additional load during the robot motion and any subsequent service operation (e.g. cleaning, diagnostics, mounting). Owing to afraid of a possible glass cracking and a subsequent destruction, the authors pay attention to an analysis of the strength of façade glass sheets being in contact with the robot holding-down vacuum system as well as with the supporting steel construction. With a view of appraising a state of stress, a computer model was build up respecting the real composition of façade glass, material properties and contact edge conditions. The paper presents achieved results by means of graphic outputs, and in conclusion, it discusses them with aim to supply owners of service robots from a sphere of the building administration a number of details.

scholarly journals Polya Counting Theory Applied to Combination of Edge Conditions for Generally Shaped Isotropic Plates

2019 ◽  
Vol 2 (2) ◽  
pp. 194-202
Author(s):  
Yoshihiro Narita
Keyword(s):  
Material Properties ◽  
Structural Design ◽  
Plate Boundary ◽  
Trial And Error ◽  
Simply Supported ◽  
Isotropic Plates ◽  
Edge Conditions ◽  
Structural Responses ◽  
Structural Behaviors ◽  
Clamped Edges

Structural behaviors of plate components, such as internal stress, deflection, buckling and dynamic response, are important in the structural design of aerospace, mechanical, civil and other industries. These behaviors are known to be affected not only by plate shapes and material properties but also by edge conditions. Any one of the three classical edge conditions in bending, namely free, simply supported and clamped edges, may be used to model the constraint along an edge of plates. Along the entre boundary with plural edges, there exist a wide variety of combinations in the entire plate boundary, each giving different values of structural responses. For counting the total number of possible combinations, the present paper considers Polya counting theory in combinatorial mathematics. For various plate shapes, formulas are derived for counting exact numbers in combination. In some examples, such combinations are confirmed in the figures by a trial and error approach.

Design on Elevate Mechanism of Large-Scale Multi-Stage Direct-Acting Hydraulic Hoist

2013 ◽  
Vol 816-817 ◽  
pp. 770-773
Author(s):  
Jing Luo ◽  
Xue Chun Liu
Keyword(s):  
Hydraulic System ◽  
Friction And Wear ◽  
Large Scale ◽  
Hydraulic Cylinder ◽  
High Rise ◽  
Multi Stage ◽  
Pipe Bursting ◽  
Direct Acting ◽  
Safety Operation

For the requirements of volume of cage, load and lifting height, Elevate mechanism of large-scale multi-stage direct-acting hydraulic hoist are adopted when construction hoist lifts material and staff in high-rise construction. Multi-stage expansion of hydraulic cylinder can cause towing oil pipe frequently. Friction and wear between oil pipe and framework is appeared, and oil pipe bursting is occurred. It directly influences both the constructing progress and safety operation. With the ingenious design of hydraulic cylinder and pipe connecting mode, oil pipe towing is avoided telescoping hydraulic cylinder. It provides a new way in other connecting mode of hydraulic system.

High-Pressure Pipelines Repaired by Steel Sleeve and Epoxy Composition

2013 ◽  
Vol 486 ◽  
pp. 181-188 ◽  
Author(s):  
Pavol Novák ◽  
Milan Žmindák ◽  
Zoran Pelagić
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Pressure ◽  
Material Properties ◽  
Welded Joint ◽  
Experimental Measurements ◽  
Filling Material ◽  
Epoxy Composition ◽  
State Of Stress ◽  
Steel Sleeve

The aim of this paper is first to determine the state of stress of welded joint repaired by steel sleeve and epoxy composition. Experimental measurements are performed on samples to determine required material properties. The structural analysis by finite element method (FEM) is performed for a pressurized pipe with insufficiently welded root and installed cold sleeve. Simulated is the case of depressurized pipes that could cause a breach of cohesion between filling material and surface of pipe or sleeve with usage of cohesive finite elements. In the end the sleeve dimensions are optimized with respect to maximum integrity to the repaired sleeve.

Multiscale Modelling of Gradual Degradation in Al2O3/ZrO2 Ceramic Composites under Tension

2010 ◽  
Vol 638-642 ◽  
pp. 2743-2748
Author(s):  
Tomasz Sadowski ◽  
Liviu Marsavina
Keyword(s):  
Material Properties ◽  
Ceramic Composite ◽  
Ceramic Composites ◽  
Multiscale Approach ◽  
Solid Modelling ◽  
Induced Anisotropy ◽  
Two Phase ◽  
State Of Stress ◽  
Ceramic Composite Materials ◽  
As Stress

Two-phase ceramic composite materials, (CMC, e.g. Al2O3/ZrO2), have a non-linear and complex overall response to applied loads due to: different phases, existence of an inital porosity, development of limited plasticity and internal microdefects. All microdefects act as stress concentrators and locally change the state of stress, leading to the development of mesocracks and finally macrocracks. Experimental results show that defects develop mainly inter-granular and cause inhomogeneity and induced anisotropy of the solid. Modelling of such material response is possible by multiscale approach describing different phenomena occuring at different scales: micro- meso- and macro- ones. The paper presents uniaxial tension process of the Al2O3/ZrO2 composite with the gradual degradation of the material properties due to different defects development.

Residual Stresses Due to Circumferential Welds

1973 ◽  
Vol 95 (4) ◽  
pp. 233-237 ◽  
Author(s):  
S. Vaidyanathan ◽  
A. F. Todaro ◽  
I. Finnie
Keyword(s):  
Residual Stresses ◽  
Material Properties ◽  
Residual Stress Distribution ◽  
Flat Plates ◽  
Circumferential Welds ◽  
Butt Weld ◽  
State Of Stress ◽  
Axisymmetric Shells ◽  
Thin Walled ◽  
Good Agreement

The residual stress distribution produced by a circumferential weld between axisymmetric shells (cylinders, spheres, cones, etc.) is quite different from that due to a butt weld between two flat plates. The reason for this difference is pointed out and it is shown that the state of stress in thin-walled shells may be estimated from that in a plate. Since a simple approximate method for predicting residual stresses in a butt-welded flat plate is available, it is possible to estimate the stresses due to a circumferential weld from the welding conditions and certain material properties. Experimental results show good agreement with the predictions.

Problems of Loading Capacity of Suction Cups in the Radial Direction

2012 ◽  
Vol 463-464 ◽  
pp. 1291-1294
Author(s):  
František Novotný ◽  
Marcel Horák
Keyword(s):  
Radial Direction ◽  
Flat Glass ◽  
Service Robots ◽  
Loading Capacity ◽  
Adhesive Properties ◽  
High Rise ◽  
Suction Cup ◽  
Plate Design ◽  
Supporting Plate ◽  
Glass Working

The paper submits a computer analysis of a vacuum gripping element, a suction cup with the rigid supporting plate, loaded radially. Results of the computer simulation are used when designing new vacuum gripping elements which have a function of a controlled modification of the friction behaviour and adhesive properties of the element contact surface with a view to increase a carrying capacity in the radial direction keeping the vacuum levels used standardly. The designed vacuum elements will be used for technologically demanding processes during flat glass working having only limited energetic connection with their vicinity, and also for robotized handling objects of the plate design. A next field of application will include an induction of hold-down forces in climbing of service robots on glass facades of high-rise buildings [1, 2].

Experimental Investigation of Trapezoidal Profile Sheeting under Varying Shear Spans

2016 ◽  
Vol 845 ◽  
pp. 148-153
Author(s):  
Avudaiappan Siva ◽  
Subramanian Swaminathan ◽  
Kumar Prasanth ◽  
R. Senthil
Keyword(s):  
Material Properties ◽  
Behavioral Changes ◽  
Structural Behavior ◽  
Shear Mode ◽  
Composite Slab ◽  
High Rise ◽  
Composite Slabs ◽  
Trapezoidal Profile ◽  
Geometrical Dimensions ◽  
Deck Slab

Composite construction method has been mainly popular due to its faster, lighter and economical methods in high rise buildings. Composite deck slab consisting of two different components, concrete being good in compression placed at the upper portion and the cold form profiled sheeting being good in resistance to tension is placed at the bottom of the deck slab. Composite slab being a combination of two different components, wide researches have been carried out to enhance the structural behavior and material properties. In this paper, trapezoidal profiled sheeting is utilized and constant geometrical dimensions are preferred throughout the study. Specimen consists of totally six numbers of trapezoidal profiled composite slabs cast using M20 grade concrete according to the recommendations of Euro code 4. Load-deflection behavior is keenly observed and recorded using the dial gauges and LVDT’s (Linear Variable differential Transducers) for comparison. When subjected to monotonic loading the composite slab specimens showed different behavioral changes in the structure at various load intervals. Out of the six specimens tested, three slabs at shorter shear spans exhibited failure at shear mode and three slabs tested at longer shear spans exhibited failure at flexure mode.

scholarly journals SOFTWARE SUPPORT DEVELOPMENT FOR NUMERICAL SOLUTION OF ANSYS CFX

2013 ◽  
Vol 7 (4) ◽  
pp. 215-221 ◽  
Author(s):  
Tomáš Brestovič ◽  
Natália Jasminská
Keyword(s):  
Heat Transfer ◽  
Material Properties ◽  
Calculated Data ◽  
Transfer Coefficients ◽  
Software Support ◽  
Significant Saving ◽  
Heat Transfer Coefficients ◽  
Ansys Cfx ◽  
Edge Conditions ◽  
Simulation Programme

Abstract The paper deals with possibilities to apply a new developed software support for simulation programme ANSYS CFX. A direct export of heat-transfer coefficients into variables used under edge conditions as well as of physical properties of gas mixtures into material properties during simulation solution of technical tasks means a significant saving of time. The paper summarizes in detail description of the software for calculation of heat-transfer coefficient during free convection (HTC-FC) and of material properties of gas mixture (MPGM) that enable to export calculated data directly into the text files which can be imported then into the programme ANSYS CFX.

The Influence of Depth-Dependent Inhomogeneity on the Contact Response of Human Patellar Cartilage

2001 ◽  
Author(s):  
Ramaswamy Krishnan ◽  
Seonghun Park ◽  
Michael A. Soltz ◽  
Robert J. Pawluk ◽  
Gerard A. Ateshian
Keyword(s):  
Articular Cartilage ◽  
Functional Response ◽  
Material Properties ◽  
Articular Surface ◽  
Solid Matrix ◽  
Homogeneous Distribution ◽  
Primary Role ◽  
Homogeneous State ◽  
Compressive Properties ◽  
State Of Stress

Abstract One of the aims of modeling articular cartilage is to determine its ability to sustain its physiological loading environment and the mechanisms by which this functional response might be compromised. It has long been hypothesized that excessive stresses in cartilage might initiate osteoarthritis, thus a determination of the state of stress within the tissue has been an important objective. It has also been hypothesized that the interstitial water of articular cartilage plays a primary role in producing low friction and wear as well as shielding the collagen-proteoglycan solid matrix from a significant portion of the loads applied across joints [1]. Furthermore, cartilage exhibits inhomogeneity through its depth, both in its tensile and compressive properties, though the significance of this inhomogeneity on the functional response of cartilage remains to be elucidated. The specific aims of the current study are to (a) experimentally determine the depth-dependent tensile and compressive properties of human patellar articular cartilage; (b) determine the response of cartilage to loading under a contact configuration using finite element models which employ these experimentally determined material properties; and (c) compare the response of the tissue to a hypothetical homogeneous distribution of material properties through the depth. The first hypothesis is that the inhomogeneity of articular cartilage acts to maximize the interstitial fluid load support at the articular surface. The second hypothesis is that the depth-dependent inhomogeneous distribution of cartilage properties acts to produce a more homogeneous state of stress than would be achieved had the properties been constant through the depth. This study extends our previous contact analyses of homogeneous cartilage layers [2,3].

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