scholarly journals Basics of Calculating Anti-Theft Crane Device from Eccentric and Tick-Borne Mechanisms

2021 ◽  
Vol 20 (4) ◽  
pp. 296-301
Author(s):  
N. M. Selivonchik ◽  
N. L. Nesterenko
Keyword(s):  
Adhesion Force ◽  
Industrial Safety ◽  
Constant Force ◽  
Wind Force ◽  
Rail Track ◽  
Rail Head ◽  
Made In

According to the requirements of the “Rules for industrial safety of cranes”, anti-theft devices must ensure that cranes under the influence of wind force stop at any point on the track, including at the junction of rails connected by side strips. Various types of anti-theft crane devices recommended for use have a number of disadvantages. Thus, the supply  of anti-theft crane devices made in the form of lever grips interacting with the rail head with mechanisms for disengaging  and converging grippers with electromechanical, electromagnetic, hydraulic or pneumatic drives complicates their design. There are also known anti-theft crane devices, in which the stopping of cranes on a rail track is carried out by a locking eccentric interacting with the surface of the rail head. The reliability of such devices is insufficient, since, due to the constant force of the spring, the adhesion force of the eccentric to the rail does not depend on the changing wind force. The paper proposes the basics of calculating the anti-theft crane device, representing the kinematic connection of two mechanisms – eccentric and thick-borne, which allows to solve a number of the above problems.

Prototype of a New Lunar-Gravity Simulator for Astronaut Mobility Studies

1969 ◽  
Vol 11 (5) ◽  
pp. 441-449 ◽  
Author(s):  
Amos A. Spady
Keyword(s):  
Support System ◽  
The Body ◽  
Research Center ◽  
Constant Force ◽  
Lunar Gravity ◽  
Air Bearings ◽  
Mobility Studies ◽  
Langley Research Center ◽  
Body Support ◽  
Made In

The results of a study of existing lunar-gravity simulators indicated that a number of improvements could be made in the simulators being used to study the effects of reduced or lunar gravity on man's self-locomotive capability. This paper presents a review of a prototype lunar-gravity simulator which was designed, built, and delivered to NASA Langley Research Center by the Case Western Reserve Institute and the Cleveland Institute of Art. The simulator utilizes novel magnetic air bearings with constant-force motors and a unique body support system in that each of the body members are independently supported.

WIND TUNNEL TEST FOR CALCULATING WIND FORCES ON SCAFFOLDS WITH BASEBOARD HEIGHT AS A PARAMETER

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Hiroki Takahashi ◽  
Katsutoshi Ohdo ◽  
Seiji Takanashi
Keyword(s):  
Wind Tunnel ◽  
Construction Industry ◽  
Wind Tunnel Test ◽  
Industrial Safety ◽  
Design Codes ◽  
Health Law ◽  
Wind Force ◽  
Force Coefficient ◽  
Safety And Health ◽  
Current Design

The Japanese Industrial Safety and Health Law was revised in March 2009 to introduce new measures concerning accidental falls in the construction industry. This revision mandates the use of guard rails, handrails, and other scaffold components. The wind load criteria and structural specifications of scaffolds are regulated by current design codes. Nevertheless, these provisions do not necessarily comply with the newly incorporated legal requirements because they apply to old-style scaffolds. This study examined the wind force on scaffolds by wind tunnel test, with baseboard height used as a parameter. The wind force coefficient of one story of scaffolds was calculated. Wind force coefficient increased as baseboard height increased. The wind force on the scaffolds equipped with baseboards is 9.2 times that on the scaffolds without baseboards. The baseboard must be greater than or equal to 15 cm to satisfy regulation requirements. The wind force coefficient of scaffolds with a 15 cm baseboard is 1.5 times that of the scaffolds without a baseboard. In scaffold design, baseboard height should be considered to guarantee a suitable wind force coefficient.

WIND TUNNEL TEST OF SCAFFOLDS SET WITH WALL CONNECTERS WITH BASEBOARD HEIGHT AS A PARAMETER

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Hiroki Takahashi ◽  
Katsutoshi Ohdo
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Wind Load ◽  
Design Guidelines ◽  
Industrial Safety ◽  
Construction Sites ◽  
Wind Force ◽  
Force Coefficient ◽  
Safety And Health ◽  
Design Calculations

The Japanese Industrial Safety and Health Law were revised in March 2009 to introduce new measures by which to prevent accidental falls in the construction industry. As part of this revision, authorities established regulations on the provision of guard rails, toe boards, mesh sheets, and other components in appropriate positions on scaffolds. When scaffolds are set in construction sites, their strength against wind force needs to be calculated. Japanese design guidelines regulate the strength of scaffolds against wind force; however, the design guidelines were written with old-style scaffolds in mind. It is not known whether the design guidelines are appropriate for new-style scaffolds. At the construction sites, the scaffolds connect to structures through the use of wall connecter, to keep scaffolds from falling down. The wind load that acts on the scaffolds was supported by the wall connecter at the construction sites. On the other hand, in conventional designs, a baseboard is used on construction sites. In this study, to set scaffolds at construction sites while using baseboard height as a parameter, we performed a wind tunnel test to examine the wind load that acts on scaffolds that have been set with wall connecters. The wind tunnel device has a total length 74,900 mm, while the device interior is 2,300 mm wide and 2,000 mm high. The load sell to set the wall connecter was used to measure wind load. The models, each of which was 1/10 in size, were used on scaffolds at general construction sites. The scaffolds were three stories high and one span wide. A baseboard was situated on one side of the long face of the scaffolds. The wind speed was set at a uniform flow of 10 m/s, because the wind force coefficient of a cylinder is stable at this speed. The characteristic length was positioned 5 mm along the diameter of a leg member. The Reynolds number was approximately 3.5 × 103. From our results, the wind force coefficient was found to increase as the baseboard height increased. With regard to efficient scaffold design, calculations of the wind force coefficient should therefore consider baseboard height.

scholarly journals Shoe Adaptation after Amputation of the II – V Phalangeal Bones of the Foot

2006 ◽  
Vol 30 (3) ◽  
pp. 324-329
Author(s):  
G. M. Rommers ◽  
H. J. M. Diepstraten ◽  
E. Bakker ◽  
E. Lindeman
Keyword(s):  
Case Reports ◽  
Spring Steel ◽  
Industrial Safety ◽  
Stair Climbing ◽  
Custom Made ◽  
Crush Injuries ◽  
Phalangeal Bone ◽  
Foot Orthosis ◽  
Made In

In The Netherlands, about 50% of all amputations of the lower limb are toes and forefoot amputations. Traumata of toes and mid-foot are rare. Preservation of the foot is the primary goal for treatment. Crush injuries of the foot may be associated with prolonged morbidity. This case study presents an insole solution for the solitary first phalangeal bone after amputation of the phalangeal bones II – V. The normal adaptation for forefoot amputations is stiffening of the sole of the shoe and a rocker bar to improve the toe off phase with load reduction of the forefoot. Because the patient had to do excessive stair climbing during work another solution was chosen. As a foot orthosis, a metal soleplate was made in order to have free movement during loading and toe-off during walking. The soleplate gives safety and provides self-adjusting properties after toe off. This enables the shoe technician to make a shoe without a rocker bar or an extra stiff insole. The 0.5 mm custom-made spring-steel plate is also used as a protective in industrial safety shoes. To improve shoe adaptation more research and case reports have to be published in order to inform doctors and shoe technicians about everyday solutions to partial foot amputations.

Prediction of Fatigue Crack Propagation of Rail Material Using 2D Finite Element Modeling

2012 ◽  
Vol 165 ◽  
pp. 16-20
Author(s):  
N.A. Akeel ◽  
Z. Sajuri ◽  
Ahmad Kamal Ariffin
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Stress Intensity ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Stress Intensity Factors ◽  
Intensity Factors ◽  
Rail Track ◽  
Rail Head ◽  
Head Surface

Fatigue crack propagation in two-dimensional rail track model under constant amplitude loading was analyzed using finite element method. The stress intensity factor was predicted using the displacement correlation method that was written in FORTRAN code and exported to Post2D to run the program and utilizing the singular elements around the crack tip area with automatic remeshing model. The fatigue crack propagation is modeled through the successive linear extensions under the linear elastic assumption. To simulate the propagation a single edge angled-crack was introduced to calculate the accurate values of stress intensity factors. The fatigue crack propagation for rail track under four point bend loading model was successfully simulated. The crack was initially propagated in direction inclined to the rail head surface but changed its direction 90° to rail head surface after certain crack length. The mix mode stress intensity factors were also successfully determined through the proposed model.

INFLUENCE OF BASEBOARD HEIGHT ON RESISTANCE TO WIND FORCE OF SCAFFOLDS AT WINDWARD SIDE OF BUILDINGS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Hiroki Takahashi ◽  
Mizuki Aoki ◽  
Katsutoshi Ohdo ◽  
Kazuo Ohgaki
Keyword(s):  
Construction Industry ◽  
Wind Tunnel Test ◽  
Design Guidelines ◽  
Industrial Safety ◽  
Windward Side ◽  
Construction Sites ◽  
Wind Force ◽  
Force Coefficient ◽  
Safety And Health ◽  
The Relationship

The Japanese Industrial Safety and Health Law was revised in March 2009 to introduce new measures by which to prevent accidental falls in the construction industry. As part of this revision, regulations on the installation of guard rails, toe boards, mesh sheets, and other components in appropriate positions on scaffolds were established. When scaffolds are installed in construction sites, their resistance against wind force needs to be calculated. Japanese design guidelines stipulate a specific scaffold resistance against wind force, but such regulations are applicable to conventional scaffolds. The problem with outdated regulations is that scaffolds are used during building construction without practitioners knowing whether the existing guidelines are suitable for new-style scaffolds. Accordingly, this study was conducted a wind tunnel test to examine the wind force exerted on building scaffolds, with the parameters being baseboard height and distance between scaffolds and a building. The relationship between the wind force coefficient of the scaffolds and baseboard height was proportional only on the scaffolds. As the distance between the scaffolds and the building lengthened, however, the relationship between the parameters reflected a steeper curve as baseboard height increased. Whenever the scaffolds were set near the building, negative pressure acted on the scaffolds as a consequence of the downwind structure. This study was examined the correction factor of the wind force coefficient of the scaffolds.

scholarly journals Spring Drive UAV Launcher

Proceedings ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 2
Author(s):  
Thanghom ◽  
Pinyochon ◽  
Narathee ◽  
Weng ◽  
Surangsee
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Initial Velocity ◽  
Mechanical Design ◽  
Design Engineering ◽  
Constant Force ◽  
Engineering Drawing ◽  
Large Area ◽  
Aerial Vehicle ◽  
The One ◽  
Made In

This paper presents the spring drive launcher for Unmanned Aerial Vehicle or UAV. Due to the absence that the UAV required large area for taking-off. However, to achieve the solution for this problem, we design spring drive launcher to bring the UAV up to the sky. The launcher allows the user to exceed the limit of take-off area and gives the highest initial velocity as possible. The research consists of the related theories which are Mechanical design, Engineering drawing, and Aerodynamic principles. Spring Drive launcher will be assembled by basic materials that must be made in order to get the prototype to be tested for achieving the goal. The results of the launcher will generate the constant force exerting on the launched UAV so it will reduce the risks for launching UAV multiple times. Besides the research can be carried on for the one who has the interest on the Spring Drive launcher.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Surface Structure in Microtomed Sections Caused by Glass and Diamond Knives

1971 ◽  
Vol 29 ◽  
pp. 456-457
Author(s):  
J. Temple Black ◽  
William G. Boldosser
Keyword(s):  
Plastic Deformation ◽  
Epoxy Resin ◽  
Carbon Coating ◽  
Surface Damage ◽  
Body Angle ◽  
Normal Manner ◽  
Bottom Side ◽  
Cutting Direction ◽  
Made In ◽  
Diamond Knife

Ultramicrotomy produces plastic deformation in the surfaces of microtomed TEM specimens which can not generally be observed unless special preparations are made. In this study, a typical biological composite of tissue (infundibular thoracic attachment) infiltrated in the normal manner with an embedding epoxy resin (Epon 812 in a 60/40 mixture) was microtomed with glass and diamond knives, both with 45 degree body angle. Sectioning was done in Portor Blum Mt-2 and Mt-1 microtomes. Sections were collected on formvar coated grids so that both the top side and the bottom side of the sections could be examined. Sections were then placed in a vacuum evaporator and self-shadowed with carbon. Some were chromium shadowed at a 30 degree angle. The sections were then examined in a Phillips 300 TEM at 60kv.Carbon coating (C) or carbon coating with chrom shadowing (C-Ch) makes in effect, single stage replicas of the surfaces of the sections and thus allows the damage in the surfaces to be observable in the TEM. Figure 1 (see key to figures) shows the bottom side of a diamond knife section, carbon self-shadowed and chrom shadowed perpendicular to the cutting direction. Very fine knife marks and surface damage can be observed.

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