scholarly journals Suggestion of Safety Certification Standards and Performance Evaluation Methods for Fabricated Mobile Scaffold in South Korea

2021 ◽  
Vol 19 (1) ◽  
pp. 133
Author(s):  
Heesoo Kim ◽  
Jeonghyeon Lim ◽  
Jeong-Hun Won ◽  
Jun-Hyuk Kwon ◽  
Seungjun Kim
Keyword(s):  
Performance Evaluation ◽  
Carrying Capacity ◽  
Evaluation Methods ◽  
Structural Safety ◽  
Structural Performance ◽  
Load Carrying Capacity ◽  
Safety Certification ◽  
Load Carrying ◽  
Certification Standards ◽  
And Performance

At construction sites, various types of temporary equipment and structures are used for safety and work efficiency. However, various temporary equipment-related accidents frequently occur for many reasons, including inappropriate installation, usage, and material and structural imperfections. A mobile scaffold is one of the most commonly used indoor temporary equipment for work in high places. In general, the main structural members of the mobile scaffold, such as the mainframes, horizontal members, braces, caster wheels, outriggers, and handrails, are installed on the construction site for this purpose. This means that the load-carrying capacity of the equipment can vary depending on the assembly details. In Korea, there are safety certification standards applied for frequently used temporary equipment, such as scaffolds and shoring. However, the standards concern the strength criteria for the member itself, rather than the global load-carrying capacity. Therefore, it is difficult to review whether the fabricated mobile scaffold has sufficient load-carrying capacity, or to confirm the structural safety considering the various uncertainties affecting the structural performance. In this study, rational safety certification standards and evaluation methods are suggested for fabricated mobile scaffolds. The suggested safety certification standards present structure-level criteria for checking the load-carrying capacity, horizontal stiffness of the structure, and overturning risk. It is expected that the structural performance for safety can be directly checked based on the suggested safety certification standards and performance evaluation methods during the safety certification stage.

scholarly journals Design of steering system of a buggy

2020 ◽  
Vol 327 ◽  
pp. 03004
Author(s):  
D. Santana Sanchez ◽  
A. Mostafa
Keyword(s):  
Carrying Capacity ◽  
Steering System ◽  
Nonlinear Finite Element ◽  
Load Carrying Capacity ◽  
Dynamic Effects ◽  
Flexural Behaviour ◽  
Steering Angle ◽  
Load Carrying ◽  
And Performance ◽  
Good Agreement

The present paper discusses the design analysis and limitations of the steering system of a buggy. Many geometrical and performance characteristics of the designed steering system were considered to address the kinematic constraints and load carrying capacity of the steering elements. Ackremann geometry approach was used to assess the limiting steering angle, while Lewis bending formula with the inclusion of dynamic effects was employed to characterise the flexural properties of the rack and pinion steering system. Analytical results were numerically verified using ABAQUS/Explicit nonlinear finite element (FE) package. Good agreement has been achieved between analytical and numerical results in predicting the flexural behaviour of the steering rack and pinion system.

Gun Bullet Deformation Analysis for Protection Board Development

2013 ◽  
Vol 577-578 ◽  
pp. 409-412
Author(s):  
Hidetoshi Sakamoto ◽  
Yoshifumi Ohbuchi ◽  
Hiroyuki Kuramae
Keyword(s):  
Carrying Capacity ◽  
Impact Load ◽  
Fem Analysis ◽  
Deformation Analysis ◽  
Load Carrying Capacity ◽  
Collision Velocity ◽  
3 Dimensional ◽  
Load Carrying ◽  
And Performance ◽  
The Impact

In this paper, the effects of collision velocity on bullet deformation were discussed and performance of protection board made of PC (polycarbonate) plate was estimated. The deformation of the bullet and the PC board after collision were measured by 3-dimensional digitizing machine.Furthermore, the bullet collision analysis was performed by FEM analysis code "LS-DYNA", and the impact load carrying capacity of PC plate was discussed by comparing the experimental results with the analytical ones

scholarly journals Manufacturing and Performance Evaluation of Carbon Fiber–Reinforced Honeycombs

2019 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
Sanjeev Rao ◽  
Jimmy Thomas ◽  
Alia Aziz ◽  
Wesley Cantwell
Keyword(s):  
Performance Evaluation ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Static Compression ◽  
Epoxy Resin System ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

In this work, the manufacturing characteristics and a performance evaluation of carbon fiber–reinforced epoxy honeycombs are reported. The vacuum-assisted resin transfer molding process, using a central injection point, is used to infuse a unidirectional dry slit tape with the epoxy resin system Prime 20 LV in a wax mold. The compression behavior of the manufactured honeycomb structure was evaluated by subjecting samples to quasi-static compression loading. Failure criteria for the reinforced honeycombs were developed and failure maps were constructed. These maps can be used to evaluate the reliability of the core for a prescribed loading condition. Improvements in the load-carrying capacity for the reinforced samples, as compared with unreinforced specimens, are discussed and the theoretical predictions are compared with the experimental data. The compression test results highlight a load-carrying capacity up to 26 kN (~143 MPa) for a single hexagonal cell (unit cell) and 160 kN (~170 MPa) for cores consisting of 2.5 × 3.5 cells. The failure map indicates buckling to be the predominant mode of failure at low relative densities, shifting to cell wall fracture at relative densities closer to a value of 10−1. The resulting energy absorption diagram shows a monotonic increase in energy absorption with the increasing t/l ratio of the honeycomb core cell walls.

Structural Performance of a Glass/Polyester Composite Wind Turbine Blade With Flatback and Thick Airfoils

2014 ◽  
Author(s):  
Xiao Chen ◽  
Zhi Wen Qin ◽  
Xiao Lu Zhao ◽  
Jian Zhong Xu
Keyword(s):  
Wind Turbine ◽  
Carrying Capacity ◽  
Local Buckling ◽  
Structural Features ◽  
Rotor Blades ◽  
Bending Test ◽  
Structural Performance ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Load Carrying

A 10.3 m wind turbine (WT) blade has been designed to improve structural efficiency of rotor blades. The blade was featured with glass/polyester composites, flatback in the inboard region, thick airfoils in the mid-span region and transversely stepped spar cap thickness. This paper provided an overview of static bending test performed on the blade. Deflections, strains, load-carrying capacity, and failure behavior of the blade were investigated. Finite element (FE) analysis was carried out to complement test and to provide more insights into structural performance of the blade. The blade exhibited linear behavior in spar caps and aft panels at the maximum chord, and it continued to withstand applied loads well beyond the occurrences of local buckling of the shear web and the flatback at the maximum chord. The inboard region showed exceptional load-carrying capacity with failure loads larger than 420% test loads. Through this study, potential structural advantages by applying proposed structural features to large composite blades for multi-megawatt (MW) wind turbines were addressed.

Design of Pre-Weakening and Evaluation of Structural Safety for Explosive Demolition of Concrete Silo

2010 ◽  
Vol 654-656 ◽  
pp. 2548-2551 ◽  
Author(s):  
So Young Park ◽  
Hoon Choi ◽  
Seung Cheol Baek ◽  
Hyo Jin Kim ◽  
Soon Jong Yoon
Keyword(s):  
Mechanical Properties ◽  
Structural Analysis ◽  
Carrying Capacity ◽  
Evaluation Method ◽  
Structural Safety ◽  
Rational Approach ◽  
Load Carrying Capacity ◽  
Expansion Joints ◽  
Load Carrying ◽  
Concrete Casting

Recently the demand for demolition of unnecessary cylindrical silo structure is increasing due to the deterioration and malfunctional conditions and the issue of demolition is in the limelight. To minimize environmental hazards caused during the process of demolition, the explosive demolition method has been applied increasingly. The concrete silo structure is often built by the slip-form method which is a continuous concrete casting operation. As a result, the structure does not have expansion joints or other structural weaknesses that can be used to assist in the demolition process. This study presents the pre-weakening of explosive demolition of the cylindrical concrete silo structure by overturning method. Pre-weakening for the explosive demolition of the structure is usually conducted based on the field experience without technical guideline for the pre-weakening procedure. Hence, there always exist safety-related concerns. To demolish the structure by blast effectively and safely, rational approach to the pre-weakening and evaluation method of the load carrying capacity of the pre-weakened structure should be established. To do this, mechanical properties of concrete are estimated by experiment prior to structural analysis. Based on the result of investigation, design or operation methods of pre-weakening for the blast demolition are discussed.

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

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