• 한국해양공학회지
• /
• 제13권2호통권32호
• /
• pp.51-57
• /
• 1999

In this study, one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by stress analysis and bending fatigue test without edge preparation, with variation of joint shape. The purpose of this study is to give the welding condiltion and design standard on manufacturing one side fillet welded T-joint. As a result, the following conclusions were obtained. 1) In one side fillet welded T-joint, the larger the leg length and the penetration depth, the greater the bending fatigue strength because reduction of stress and strain on toe and root. The increase of the longitudinal leg length rather than vertical leg length contributed to the increase in bending fatigue strength. 2) In one side fillet welded T-joint without edge preparation, both general manual welding and general automatic welding were carried out with same condition. In this case, automatic welding showed deeper penetration and more increased longitudinal leg length than manual welding, so that automatic welding offers greater bending fatigue strength. 3) For one side fillet welded T-joint without edge preparation with automatic welding, the ratio(h/t) of the leg length(h) and the main plate thickness(t) in which toe crake can occur was 1.0 over.

• Journal of Welding and Joining
• /
• 제16권5호
• /
• pp.134-141
• /
• 1998

In this study, a fillet size for bending fatigue strength of one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by bending fatigue test with or without edge preparation and burn through, with variation of joint shape. As a result, the following conclusions were obtained. (1) In one side fillet welded T-joint, the larger the leg length, the greater the bending fatigue strength. The increase in bending fatigue strength. (2) One side filet welded T-joint with edge preparation showed higher bending fatigue strength than that with twofold-large leg length and without edge preparation. (3) In one side fillet welded T-joint without edge preparation, both manual welding and automatic welding were carried out with same condition. In this case, automatic welding shoed deeper penetration and more increased horizontal leg length than manual welding, so that automatic welding offers grater bending fatigue strength. (4) For one side fillet welded T-joint without edge preparation, the ratio(h/t) of the leg length (h) and the main plate thickness (t) in which toe crack can occur was 1.2 over. (5) In one side fillet welded T-joint with edge preparation, the burn through led to reduced bending fatigue strength. However, this bending fatigue strength was higher than that of one side fillet welded T-joint without edge preparation and with a larger leg length.

• Journal of Welding and Joining
• /
• 제7권4호
• /
• pp.22-29
• /
• 1989

In this paper weld distortion both in butt and fillet welds by flux cored arc welding has been investigated by changing welding parameters such as heat input and plate thickness, and the weld distortion was expressed as a function of welding parameters adopting the inherent strain theory as proposed by Watanabe and Satoh in 1961. As results of the research it is proposed that transverse shrinkage in root pass butt welds in proportional to ln[(Q/t_-tan.theta.] where Q is heat input(cal/mm), t is plate thickness(mm), and 2.theta. is groove angle(degree), and angular distortion .phi.(radian) in one pass of fillet welds has the following relationship: .phi..var.(Q/ $t^{1.5}$)$^{3}$exp[-(Q/ $t^{1.5}$ )$^{2}$3/] These equations provide us with basic tools to predict the amount of weld distortion in welded structures.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.1058-1062
• /
• 1996

The assessments of weld defects by fracture mechanics are performed for design of welded Joints. In general, butt, T-type, and L-type welded joint are useful for welding structure. When linear weld defects are in welded joint, stress intensity factors for each joints are calculated by finite element method. Analysis results are shown for the fracture modes and characteristics of joint types. And they are founded for the weaken order of welded joints being T-type, butt, L-type.

• International Journal of Ocean System Engineering
• /
• 제2권2호
• /
• pp.82-91
• /
• 2012

Fillet welding is widely used in the assembly of ships and offshore structures. The T-joint configuration is frequently reported to experience fatigue damage when a marine structure meets extreme loads such as storm loads. Fatigue damage is affected by the magnitude of residual stresses on the weld. Recently, many shipping registers and design guides have required that the fatigue strength assessment procedure of seagoing structures under wave-induced random loading and storm loading be compensated based on the effect of residual stresses. We propose a computational procedure to analyze the residual stresses in a T-joint. Residual stresses are measured by the X-ray diffraction (XRD) method, and a 3-D finite element analysis (FEA) is performed to obtain the residual stress profile in the T-joint. The proposed finite element model is validated by comparing experiments with computational results, and the characteristics of the residual stresses in the T-joint are discussed.

• 대한조선학회지
• /
• 제12권2호
• /
• pp.35-42
• /
• 1975

This paper investigates the distribution of stress and its behavior at the Root Toe in fillet welding joint. Furthermore, the stress components and principal stresses in the fillet welds are calculated by the finite element method. The distribution of stresses obtained numerically by means of the finite element method is also compared with the experimental results of two dimensional photoelasticity. A Cover plate type and Center block type of fillet welds are used as models for the numerical calculations covering the variations of 2 W/M(thickness of main plate/thickness of cover plate)=1 through 2W/M=4. The results obtained in these studies are summarized as follows; 1) When W2/M values become small, the stress concentration factors of the Root are larger than of the Toe in a C-type. Its critical value is 2W/M=3.00. However, no critical value exists in a T-type. 2) For 2W/M Values being avove 3.5 in a C-type and above 4.0 in a T-type, $K_R$ and $K_{\tau}$ become 1. 3) According to the differences of 2W/M values, the differences in stress become increasing in the Root but become decreasing in the Toe. These differences, however, disappear as the free boundary surface is approached. 4) The stress concentration factors of both the Root and Toe obtained by means of the finite element method have somewhat lower values than obtained by the photoelasiticity. But their principal stress directions coincide in either method. 5) It proves beneficial to employ the finite element method for two-dimensional plane stress analysis in front fillet welding joint.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2006년 추계학술발표대회 개요집
• /
• pp.216-218
• /
• 2006

The application of aluminium alloy is increasing for lightweight and high quality transport vehicle. In this study, therefore, it is intended to apply the high speed hybrid welding method for marine grade aluminium alloy(A5083) used for shipbuilding that consists of 3 kW CW Nd:YAG laser and MIG welding process. For this purpose, the characteristics of process parameters(laser & arc combine angle and focal position of hybrid head to specimen) are investigated for hybrid fillet joint. This study also describes determination of heat distribution using finite element model of the T-joint fillet weld using the in-house solver which has been validated for different type of welding problems.

• Structural Engineering and Mechanics
• /
• 제83권5호
• /
• pp.693-707
• /
• 2022

Bonded joints have proven their performance against conventional joining processes such as welding, riveting and bolting. The single-lap joint is the most widely used to characterize adhesive joints in tensile-shear loadings. However, the high stress concentrations in the adhesive joint due to the non-linearity of the applied loads generate a bending moment in the joint, resulting in high stresses at the adhesive edges. Geometric optimization of the bonded joint to reduce this high stress concentration prompted various researchers to perform geometric modifications of the adhesive and adherends at their free edges. Modifying both edges of the adhesive (spew) and the adherends (bevel) has proven to be an effective solution to reduce stresses at both edges and improve stress transfer at the inner part of the adhesive layer. The majority of research aimed at improving the geometry of the plate and adhesive edges has not considered the effect of temperature and water absorption in evaluating the strength of the joint. The objective of this work is to analyze, by the finite element method, the stress distribution in an adhesive joint between two 2024-T3 aluminum plates. The effects of the adhesive fillet and adherend bevel on the bonded joint stresses were taken into account. On the other hand, degradation of the mechanical properties of the adhesive following its exposure to moisture and temperature was found. The results clearly showed that the modification of the edges of the adhesive and of the bonding agent have an important role in the durability of the bond. Although the modification of the adhesive and bonding edges significantly improves the joint strength, the simultaneous exposure of the joint to temperature and moisture generates high stress concentrations in the adhesive joint that, in most cases, can easily reach the failure point of the material even at low applied stresses.

• Journal of Welding and Joining
• /
• 제21권5호
• /
• pp.568-574
• /
• 2003

In the welding for the steel structure of H-beam with mild steel and 490N/$\textrm{mm}^2$ high tensile steel, we applied the fillet weld mostly and 6-8mm weld length(AISC-spec.). And a new developed metal-cored-wire is used in automatic welding as well as semi-automatic welding. In this study we have attempted to raise the welding productivity and to stabilize the quality on horizontal positions of fillet welding with the following items: - We improved the weld productivity using metal based cored wire with a high deposition rate in the steel structure of H-beam. - We tested the weldability and evaluated the quality of the weldmetal by horizontal fillet $CO_2$ welding. The process is carried out in combination with a special purpose metal-based FCW with excellent resistance to porosity and high welding speed. - We studied the micro structure of the weldmetal by the various welding conditions. - We studied the effect of welding residual stress by the welding conditions in T-joint. Therefore, it can be assured that more productive and superior quality of the weldmetal can be taken from this study results.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 1998년도 특별강연 및 춘계학술발표 개요집
• /
• pp.42-45
• /
• 1998