• Journal of the Korean Society of Safety
• /
• v.26 no.2
• /
• pp.1-5
• /
• 2011

In order to evaluate fatigue endurance for an ultra-light weight inline skate frame, FEM analysis was performed. Tensile properties and a S-N curve were determined through tensile and fatigue tests on a modified Al-7075+$S_c$ alloy. The yield and ultimate tensile strengths were 553.3 MPa and 705.5 MPa, respectively. The fatigue endurance limit of this alloy was 201.2 MPa. For evaluating the fatigue endurance of the inline skate frame, the S-N data were compared with the stress analysis results through FEM analysis of the frame. The maximum Von-Mises stress of the frame was determined 106 MPa through FEM analysis of the frame, assuming that the rider weight is 75 Kg. Conclusively, on the basis of fatigue limit, the inline skate frame has a safety factor of approximately 2.0.

• Journal of the Korean Society of Safety
• /
• v.22 no.3 s.81
• /
• pp.1-6
• /
• 2007

In order to evaluate fatigue endurance for the rocker arm of a diesel engine, stress measurements were performed using the strain gages attached near the neck, where is one of the most critical region in the rocker arm, in variation of the engine speed. The fatigue life experiments were carried out on miniature specimens from the rocker arms. For evaluating the fatigue endurance of the rocker arm, the S-N data were compared with the stress analysis results through FEM analysis of the rocker arm. The effective stress of the neck region was determined 17.7MPa through FEM analysis of the rocker arm. Conclusively, on the basis of fatigue limit, the rocker arm has a safety factor of 2.8 or 3.4 from the stress measurement or FEM results, respectively.

• Journal of Auto-vehicle Safety Association
• /
• v.14 no.3
• /
• pp.30-34
• /
• 2022

The CFT(Cornering Fatigue test) and RFT(Radial Fatigue Test) are tests for evaluating the endurance of the disc and rim region of the wheel. In recent, automobile wheel safety standards have been revised and the applied load and target life criteria are different from existing conditions. The verification evaluation of all wheels requires a lot of time and cost. In this study, the endurance severity of each test was compared through strain-life approach by selecting 4 steel and 8 aluminum wheels.

• Journal of the Korean Society of Safety
• /
• v.28 no.3
• /
• pp.1-5
• /
• 2013

In order to evaluate fatigue endurance for an MTB(mountain bike) frame, FEM(finite element method) analysis was performed. For evaluating the fatigue endurance of the MTB frame, the S-N data for Al-6061 fillet weldment were compared with the stress analysis results through FEM analysis of the frame. Three loading condition, pedalling, horizontal and vertical loading conditions were considered for fatigue endurance evaluation. Horizontal loading(+1200 N) condition was found to be the most severe to the frame. The maximum von Mises stress of the frame under horizontal loading(+1200 N) condition was determined 294 MPa through FEM analysis of the frame. Conclusively, on the basis of fatigue strength of 200 MPa at the number of cycles of 50,000, the MTB frame has an improper safety factor of approximately 0.25, suggesting that this frame needs reinforcement.

• Journal of the Korean Society of Safety
• /
• v.35 no.4
• /
• pp.15-22
• /
• 2020

Scaffolding works are demolished after this structure is completed, and safety accidents often occur because they are installed differently from legal standards or frequently change during work. Therefore, in order to strengthen the safety of scaffolding, the Ministry of Land, Infrastructure and Transport required a need for design standards for temporary facilities that can systematically prevent and solve large-scale safety accidents that are repeatedly increasing during temporary construction. It has been enacted, and some contents have been revised for the past three years. However, construction site personnel do not know or know the revised matters, but often install scaffolding by the installer's experience rather than complying with relevant laws and regulations. It is the situation that the ground strength test of the foundation ground for the load applied to the floor of the column is omitted in most sites. Therefore, this study grasped the actual situation on the degree of recognition of the revised laws and regulations of the construction site and the foundation-based treatment of the floor working load of the scaffolding column, and derived problems. In addition, we intend to provide reference materials for the endurance test according to the ground conditions to small-scale small sites where it is difficult to conduct the test by carrying out the endurance test of the scaffolding ground according to the revised standards.

• Fire Science and Engineering
• /
• v.2 no.2
• /
• pp.17-30
• /
• 1988

In Our Country, the fire safety design is done by the standard furnace fire test. This is haphazard procedure, as the standard furnace fire endurance of structural elements has little relation to the structural element endurance in an actual Compartment fire. The standard furnace fire test results, though obtained at great cost, do not contribute to the understanding of the behavior of structural elements in an elevated temperature environment and can not be applied rationally in fire safety design. The response of a steel and reinforced concrete structure in fire is a very complex problem. Therefore, in this paper is explained about tendency of study for fire safety design in advanced nations.

• Journal of Aerospace System Engineering
• /
• v.1 no.3
• /
• pp.13-20
• /
• 2007

The objective of this study is to investigate endurance test of localization part for T-50 aircraft engine. Major localization parts of the engine (F404-STW-102) was performed using Accelerated Simulated Mission Engine Test. The purpose of this test is to evaluate of quality demonstration capability, to verify design of engine localization parts, and to improvement safety and operation rate of T-50 advanced trainer by finding out operational problems in production phase and fixing it.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.421-424
• /
• 2006

This study, in order for perceiving the mechanical attribute followed by the explosive spalling of high strength concrete material under high temperature and evaluating capacity of endurance of material, targets understanding capacity of endurance of material such as explosive spalling in high temperature, temperature by thickness of clothing, transformation extent, transformation speed and displacement, stocking the maximum load based on the Allowable Stress Design Method. As a result of experimenting the explosive spalling attribute of high strength concrete material, the one possibly causing serious damage is the 50 MPa concrete. In all aspects of 60 MPa concrete, explosive spalling happens. Especially, it is hazardous enough to reveal all the iron bar. All explosive spalling is intensively concentrated on the surface of concrete for the first $5{\sim}25$ minutes, which urges for the explosive spalling protection action. As a result of evaluating the structural safety by the transformation of high strength concrete, while beam assures the fire safety meeting regulation, 60 MPa shows the dramatic increase of transformation, which only counts 84% of safety. In a column, both the concrete exclusion and excessive explosive spalling are concentrated upper part of column, which brings about the dramatic transformation, so it only meets the 50% of safety regulation. Likewise, in 80, 100 MPa concrete which was never experimented considering the condition of domestic structural endurance stocking devices, the faster collapse is expected.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.1429-1433
• /
• 2004

Recently, a dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOK corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque form input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element methode and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test methode when applied rated torque.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.6 s.171
• /
• pp.47-54
• /
• 2005

A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.