• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.859-864
• /
• 2004

In this study, we compared the fatigue characteristics of weld metal with those of base metal. Also we examined the influence of heat treatment and weld bead profiles for the fatigue life of weld metals. From the experimental results, it was seen that the fatigue characteristics of welded specimens with a grinded toe of bead are slightly better than those are not grinded. Also the fatigue life is affected more by the stress concentration on the profile change in the weld toe rather than by residual stress influence, because the fatigue characteristic of weld metals was not influenced whether the heat treatment is conducted or not.

• Journal of Welding and Joining
• /
• v.28 no.6
• /
• pp.45-50
• /
• 2010

Most of joining processes for machine and steel structure are performed by butt and fillet welding. The mechanical properties and fatigue strength of their welding zone can be effected largely by the differential of generated heat and changes of grain size according to thickness of material and number of passes in welding process. In this study, it was investigated about characteristics of fatigue failure according to thickness of material and number of passes in cruciform fillet weld zone as the basic study for safe and economic design of welding structures. Fracture modes in cruciform fillet weld zone are classified into toe failure and root failure according to non-penetrated depth. It can be accomplished economic design of welding structures considering fatigue strength when the penetrated depth in fillet weld zone is controled properly.

• Journal of Korean Foot and Ankle Society
• /
• v.15 no.3
• /
• pp.183-186
• /
• 2011

Extensor hallucis brevis (EHB) is only extensor of the first metatarsophalangeal (MTP) joint after modified Jones procedure. Therefore preserving the normal insertion of the EHB has been emphasized during that procedure. We experienced a case of EHB rupture after modified Jones procedure and had satisfied surgical outcome by partial transfer of extensor digitorum longus (EDL) of second toe.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.928-933
• /
• 2009

The purpose of this study is to examine the energy consumption, carbon dioxide emission & energy cost of district heating using sewage source. The annual TOE of heat pump using sewage source save 37.1 percent than city gas boiler. And annual carbon dioxide emission of heat pump cut down 41.3 percent than city gas boiler. If it charges the rate schedule for district heating to apartment resident, collected amount are 3,127,170 thousand won. As energy cost of heat pump & circulation pump are 1,378,072 thousand won. the profits are 1,749,098 thousand won. As payback period is 8.97years, applicability is low level. However, it has advantages in energy consumption, carbon dioxide emission & energy cost. Therefore, it needs to proceed through government assistance.

• Proceedings of the KWS Conference
• /
• 2004.05a
• /
• pp.252-254
• /
• 2004

Fatigue life a box weldment was predicted with the stress concentration and residual stress using the equation reported. In order to change the stress concentration and residual stress of the box weldment, Post treatments such as smooth grinding of weld bead, weld toe grinding and hammer peening were applied. The fatigue life of the weldment after post treatment clearly increased, which is attributed to the reduction of stress concentration and/or introduction of compressive residual stress at the weld toe. The predicted fatigue life was a relatively good agreement with the experiment for a long fatigue life, while it was underestimated for a short fatigue life.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.5
• /
• pp.113-119
• /
• 2012

CTBA(Coupled Torsion Beam Axle) has been adapted as the rear suspension of a compact car. Because that has the advantage of cost and weight in comparison with multi-link type. But CTBA has the disadvantage in vehicle stability to become oversteer occurring toe-out of the rear wheel when cornering and braking. In this study, we suggested CTBA Geometry Compensation System to overcome the disadvantage of CTBA. We predicted braking and cornering vehicle performance from proposed equation and numerical simulation. And also, the results were compared to objective and subjective evaluation in vehicle.

• Journal of Korean Foot and Ankle Society
• /
• v.20 no.1
• /
• pp.32-35
• /
• 2016

We reported on a rare case of recurred macrodystrophia lipomatosa of the foot, and reviewed the literature. A 62-year-old male patient presented with right foot second toe pain; preoperative magnetic resonance imaging and radiograph examination was performed. After surgery the biopsy confirmed the diagnosis. American Orthopaedic Foot and Ankle Society score was checked before and after surgery. Wide excision of the affected area including ray amputation is an effective way to prevent recurrence and relieve the pain after surgery. The 2nd toe ray amputation was performed in the treatment of recurred macrodystrophia lipomatosa of the foot, and is thought to be an effective way to relieve pain and prevent recurrence. After minimally invasive surgery with complete excision surgery, additional data on recurrence and pain relief rate are needed.

• Journal of Welding and Joining
• /
• v.26 no.6
• /
• pp.97-102
• /
• 2008

It is well known that there exist two typical fatigue crack initiation locations in ship structures: one is the weld toe and the other is the weld root where partial penetration weld is performed. In particular, it is important for fillet weldments to avoid weld root cracking in order to prevent catastrophic failure particularly in ship structures. Therefore detail considerations are required for cruciform joints with partial penetration when there is a possibility of weld root crack initiation. For these reasons, fatigue tests on welded joints were performed in this study. Concept of stress intensity factor(SIF) by means of fracture mechanics is applied for predicting fatigue life of fillet welded joints.

• Journal of the Society of Naval Architects of Korea
• /
• v.33 no.4
• /
• pp.133-141
• /
• 1996

The mode of fatigue failure is depended on the characteristics of the fatigue crack initiated and propagated from the weld toe and the weld root in the load-carrying fillet welded joints. The characteristics of fatigue crack are deeply affected by the geometry of fillet and the stress range. The purpose of this study is to investigate critical weld size and stress range in order to occur toe failure under pulsating tension loading in the load-carrying fillet welded cruciform joints.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.839-844
• /
• 2007

In order to reduce resultant stress of the connection detail of longitudinal and rib and floor beam, in this study, the parameter studies for the reinforcement details as the bulk head and the vertical rib were preformed with FE analysis. As the result, it was shown that reinforcement detail with the bulk head plate in longitudinal rig reduced generally the principal stress at the connection detail, but the stress concentration of the weld toe parts occurring fatigue crack increased. However, it was known that the reinforcement detail with the vertical rib in the rib is more effective than the bulk head plate of the reduction stress concentration in the weld toe parts.