Stress concentration and strength prediction of 2×2 twill weave fabric composite with a circular hole

2018 ◽  
Vol 53 (4) ◽  
pp. 463-474 ◽  
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Bülent Acar

Stress concentration and strength prediction of 2 × 2 twill weave carbon fiber reinforced composite specimens with different hole sizes are investigated on numerical and analytical basis. Stress distribution around the hole is obtained using Lekhnitskii’s model together with Tan’s finite width correction factor and also finite element analysis. Validity of Lekhnitskii’s formula together with Tan’s correction is demonstrated for 2 × 2 twill weave composites with different w/d ratios. Tan’s correction factor is compared with finite element analysis results at a characteristic distance away from hole tip where the stresses are important for strength prediction. Applicability of point stress criteria and average stress criteria strength prediction methods for open hole specimens to 2 × 2 twill weave material is demonstrated. The performances of the point stress criteria and average stress criteria methods are compared in the case of eccentric tension loading. All analytical and numerical results are verified by experimental study.

2019 ◽  
Vol 13 (3) ◽  
pp. 5242-5258
Author(s):  
R. Ravivarman ◽  
K. Palaniradja ◽  
R. Prabhu Sekar

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.


2012 ◽  
Vol 538-541 ◽  
pp. 3253-3258 ◽  
Author(s):  
Jun Jian Xiao

According to the results of finite element analysis (FEA), when the diameter of opening of the flat cover is no more than 0.5D (d≤0.5D), there is obvious stress concentration at the edge of opening, but only existed within the region of 2d. Increasing the thickness of flat covers could not relieve the stress concentration at the edge of opening. It is recommended that reinforcing element being installed within the region of 2d should be used. When the diameter of openings is larger than 0.5D (d>0.5D), conical or round angle transitions could be employed at connecting location, with which the edge stress decreased remarkably. However, the primary stress plus the secondary stress would be valued by 3[σ].


2007 ◽  
Vol 353-358 ◽  
pp. 1995-1998
Author(s):  
Byeong Choon Goo

The purpose of this paper is to develop an estimation formula of stress concentration factors of butt-welded components under tensile loading. To investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints, butt-welded specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius, flank angle and bead height were measured by a profile measuring equipment. By using the measured data, the influence of three parameters on the stress concentration factors was investigated by a finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. According to the simulation results, a formula to estimate the stress concentration factors of butt-weld welded structures was proposed and the estimated concentration factors from the formula were compared with the results obtained by the finite element analysis. The two results are in a good agreement.


2006 ◽  
Vol 22 (01) ◽  
pp. 15-20
Author(s):  
Shou-Hsiung (Vincent) Hsu ◽  
Jong-Shyong Wu

Cutting total man-hours is one of the most effective ways of reducing costs in a shipyard and, in general, designing structures with fewer pieces will achieve the goal of reducing man-hours. The Capesize bulk carrier, due to requirements for access, ballast capacity, and double-bottom height, always has a pipe duct in the center part of the double bottom. Comparison between two existing Capesize bulk carriers reveals that one may eliminate more than 1,800 structural pieces (about 2.6% of the total number of ship pieces) if the conventional longitudinal reinforced pipe duct is replaced by a transverse reinforced one. Further, from the finite element analysis (FEA) results using the SafeHull computer package of the American Bureau of Shipping (ABS), it has been found that the vertical deflection and stress concentration of the double bottom are improved and some of the thicker plates can be removed if the transverse reinforced pipe duct is used. Therefore, the overall steel weight for the Capesize bulk carrier using the transverse reinforced pipe duct was found to be less than that using the longitudinal reinforced pipe duct.


2019 ◽  
Vol 52 (6) ◽  
pp. 521-536
Author(s):  
R Karthikeyan ◽  
S Rajkumar ◽  
R Joseph Bensingh ◽  
M Abdul Kader ◽  
Sanjay K Nayak

Present research endeavours towards the development of a methodology to enhance the life of hyperelastic materials in automotive suspension (leaf spring) system. The durability of the elastomeric (rubber) material in the insert was determined at various loading conditions for better operation. Three different rubber materials were used as the models including the currently used rubber material in the suspension system. The non-linear finite element analysis was carried out for the three different materials with the uniaxial stress–strain data as the input source for the material properties. A suitable hyperelastic model was also used as the input for determining the deformation and the stress concentration in the leaf spring tip insert. The failure of the tip insert was determined in various loading conditions and the best design for limited stress concentration with higher reliability was determined in the three models. The overall results are tabulated and compared for better utilization of rubber as a tip insert in the automotive industry.


Author(s):  
Yuhui Huang ◽  
Chengcheng Wang ◽  
Shan-Tung Tu ◽  
Fu-Zhen Xuan ◽  
Takamoto Itoh

Finite element analysis is adopted to study the stress concentration of pit area under tension-torsion loading. The stress concentration factors under regular evolution and irregular evolution of pits are investigated by conducting a series of three-dimensional semi-elliptical pitted models. Based on the finite element analysis, it can be concluded that pit aspect ratio (a/2c) is a significant parameter affecting stress concentration factor (SCF) for regular evolution pits. Pits, having higher aspect ratio, are very dangerous form and can cause significant reduction in the load carrying capacity. When local dissolution occurs in the pitting area, SCF will have a sharp increase, it is more probable for a crack to initiate from these areas compared with pits for regular evolution. Furthermore, local dissolution coefficient is proposed to study effect of local dissolution within the pit on SCF.


2014 ◽  
Vol 889-890 ◽  
pp. 1406-1409 ◽  
Author(s):  
Ming Jian Jian ◽  
Guang Cheng Zhang ◽  
Du Qing Zhang

By finite element software ANSYS a model of GIS busbar tube was established for investigating the effect of the gas pressure on the shell. The results shows that the stress concentration degree is higher on the shoulder between the main tube and the branch pipes under the internal pressure and the gravity, and the highest value is 44.92MPa which is far lower than the admissible stress. Stress changed along the thickness direction, and its value decreased gradually from the inside out. The distributions of the strain and deformation are similar to that of the stress.


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