An analytical solution for the stress distribution within a spherically isotropic hollow sphere under diametrical compression

2018 ◽  
Vol 24 (5) ◽  
pp. 1256-1278 ◽  
Author(s):  
Lintong Yan ◽  
Xuexia Wei
Keyword(s):  
Analytical Solution ◽  
Shear Modulus ◽  
Tensile Stress ◽  
Hollow Sphere ◽  
Hollow Spheres ◽  
Maximum Tensile Stress ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Inner Surface ◽  
Symmetric Deformation

An analytical solution for the stress distributions within a spherically isotropic hollow sphere under diametrical compression is derived. The deformation of the spherically isotropic hollow sphere is divided into axis-symmetric deformation and non-symmetric deformation. The analytical solution for the axis-symmetric deformation is obtained by following the displacement method, while that for non-symmetric deformation of the spherically isotropic hollow sphere is obtained by employing the displacement function method. When the isotropic limit is considered, the analytical solution for isotropic hollow spheres is recovered identically. Numerical results show that tensile stress concentrations are usually developed both at the inner surface and near r/ R = 0.85 within a hollow sphere along the axis of loading. A small value of the anisotropy in Young’s modulus or Poisson’s ratio usually leads to a large value of the maximum tensile stress at the inner surface. While a smaller value of the anisotropy in Poisson’s ratio or a large value of the anisotropy in the shear modulus may lead to a large value of the maximum tensile stress near r/ R = 0.85 for a thick and anisotropic hollow sphere. In addition, it is found that the anisotropy in the shear modulus has drastic influence on the tensile stress distributions within a thin hollow sphere, and a particular value of the anisotropy in the shear modulus may reduce greatly the tensile stress concentrations both at inner surface and near r/ R = 0.85 of a thin hollow sphere. This result may provide us a very attractive method to optimize the elastic constants of anisotropic hollow spheres by synthesis process technique so as to improve the load capacity of a hollow sphere, and extend the fatigue life of composite material made of thin hollow spheres.

Finite-element analysis of stresses in shafts due to interference-fit hubs

1969 ◽  
Vol 4 (2) ◽  
pp. 105-114 ◽  
Author(s):  
D J White ◽  
J Humpherson
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Maximum Tensile Stress ◽  
Stress Distributions ◽  
Local Pressure ◽  
Element Analysis ◽  
Interference Fit ◽  
Axial Tensile ◽  
Stress Relieving ◽  
Transition Radius

Stress distributions in shafts due to interference-fit hubs are presented for shafts with various hub-seat features. For the calculations axisymmetric finite-element computer programmes were used. In a plain shaft there is a high local pressure just inside the hub face and a high axial tensile stress just outside it. These stresses are relieved by features, such as fillets or grooves in the shaft, arranged to give a raised or isolated hub seat and, of the two, a raised seat with a transition radius is more effective than a stress-relieving groove. Hubs fitted on either side of a groove reduce the maximum tensile stress compared with a single hub, while overhung hubs produce no significant change compared with flush hubs. Methods of fitting which promote axial constraint between the hub and shaft should be avoided since this leads to an increase in tensile stress in the shaft.

Finite Element Analysis of an Involute Spline

2000 ◽  
Vol 122 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Zella L. Kahn-Jetter and ◽  
Suzanne Wright
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Contact Stress ◽  
Maximum Tensile Stress ◽  
Initial Contact ◽  
Stress Concentrations ◽  
Entire Cross Section ◽  
Element Analysis ◽  
Low Torque ◽  
Involute Spline

Two finite element analyses of an involute spline are performed; one is axisymmetrically loaded and the other is nonaxisymmetrically loaded. An entire cross section of both an internal and external pair is analyzed for both models. It is shown that on the axisymmetrically loaded spline the highest stress experienced is the maximum compressive contact stress although the tensile stress in the shaft is also quite high. It is also shown that stress concentrations exist at the root and top of the tooth for both models. Furthermore, on the nonaxisymmetrically loaded spline at low torque, only a few teeth make initial contact, however, as torque is increased, more teeth come in contact. All the stresses remain relatively constant under increasing torque as more teeth are engaged. Once all teeth are in contact stress increases with higher torques. However, the maximum tensile stress (arising from stress concentrations) remains fairly constant, even at high torques, because the stress concentrations that occur at tooth roots appear to be relatively independent of the number of teeth in contact. [S1050-0472(00)00102-1]

scholarly journals Stochastic finite element analysis of the diametral compression test of powder compacts and porous materials

2021 ◽  
Author(s):  
Jose Andres Alvarado-Contreras ◽  
Alexis Andres Lopez-Inojosa
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Compression Test ◽  
Maximum Tensile Stress ◽  
Stress Distributions ◽  
Element Analysis ◽  
Diametral Compression ◽  
Powder Compacts ◽  
Porosity Heterogeneity ◽  
Diametral Compression Test

Abstract This paper presents a stochastic finite element approach for modeling the mechanical behavior of powder compacts and porous materials under diametral compression test conditions. The main goal is assessing the validity of the diametral compression test as an indirect technique to estimate tensile strengths of brittle or quasi-brittle materials exhibiting porosity heterogeneity. Thus, the study seeks to predict the influence of porosity randomness on stress distributions and the spatial location of the highest tensile stress on thin disc-shaped specimens. The proposed formulation uses a stochastic framework that couples a random spatial field to the finite element analysis to include non-deterministic features. Two case studies consider comparable targets for the mean porosity but different coefficients of variations. For each case study, a total of 1000 realizations are conducted under identical loading and boundary conditions. The predicted stress distributions are compared to the ones from homogenous closed-form solutions from the literature. Then, the expected magnitude and location of the maximum tensile stress are evaluated by statistical means. Findings from the stochastic model show that porosity randomness induces stress concentration around less dense volumes and location deviation of the maximum tensile stress from the center of the discs. Likewise, porosity heterogeneity could affect the accuracy of experimental diametral compression tests even for small variance cases; and so, the reliability of the mechanical properties derived from models based exclusively on the classic assumption of material homogeneity.

Heating Steady Thermal Stress in a Composite EFBF Plate Made of Ceramic/FGM/Metal Considered Temperature Dependency

2009 ◽  
Vol 417-418 ◽  
pp. 537-540 ◽  
Author(s):  
Yang Jian Xu ◽  
Dai Hui Tu
Keyword(s):  
Thermal Stress ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Composite Plate ◽  
Maximum Tensile Stress ◽  
Metal Composite ◽  
Temperature Dependency ◽  
Stress Distributions ◽  
Maximum Compressive Stress ◽  
Layered Ceramic

A NFE model is constructed to analyze the heating steady thermal stress in a ceramic/FGM/metal composite EFBF plate considered temperature dependency. From numerical calculation, when T0=Ta=300K and Tb=1 000K, the stress distributions in the plate were obtained. The results are as follows. With the increase of the FGM thickness, the stress distribution is more reasonable, and the largest tensile stress reduces by 45.64%. With the increase of M, the stress change increases obviously, and the compressive stress on the surface of ceramics reduces by 56.0%. Compared with A=0, the compressive stress of A=3.99 on the surface of metal increases by 94.2%, and the stress on the surface of ceramics changes from compressive stress to tensile stress. When T0=300K, Ta=700K, compared with Tb=1 050K, when Tb=1 800K, the compressive stress on the surface of metal increases 13.62 times, and the maximum compressive stress on the surface of ceramics increases 5.22 times. Compared with the two-layered ceramic/metal composite plate, the stress of ceramic/FGM/metal composite EFBF plate is very gentle, and the maximum tensile stress reduces by 44.2%. Compared with constant material properties, the maximum compressive stress on the surface of metal considered temperature dependency reduces by 59.1%. The results provide the foundations of theoretical calculation for the design and application of the composite plate.

Application of a chamfer slab technology to reduce internal cracks of continuous casting bloom during soft reduction process

2019 ◽  
Vol 116 (6) ◽  
pp. 608 ◽  
Author(s):  
Nanfu Zong ◽  
Hui Zhang ◽  
Minglin Wang ◽  
Zhifang Lu
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Continuous Casting ◽  
Three Dimensional ◽  
Reduction Process ◽  
Element Model ◽  
Maximum Tensile Stress ◽  
Stress Concentrations ◽  
Soft Reduction ◽  
The Right

The stress concentrations over the brittle temperature range (BTR) in the bloom continuous casting are the main reason of internal cracks. In order to analyze the stress distribution in the BTR of the blooms during soft reduction stage, a three-dimensional thermo-mechanical finite-element model with different corner structures (i.e. chamfer angle and chamfer length) was established. The relationship between corner structures, maximum tensile stress, as well as shear stress is analyzed, and the influence of corner structure of bloom on the internal cracks is studied. The results show that the tensile stress and the shear stress decreased gradually by properly adjusting the chamfer angle and the chamfer length of the bloom. Compared with the use of the right-angle bloom casting, the application of chamfer bloom casting is able to reduce the stress concentration over the BTR, therefore reduces the internal cracks. In addition, as a side benefit, the chamfer bloom casting can save energy required in deforming the bloom during the soft reduction process.

Stress-Distribution around Pin-Loaded Hole for Orthotropic Laminates

2016 ◽  
Vol 842 ◽  
pp. 53-60
Author(s):  
Syarif Hidayat ◽  
Bambang K. Hadi ◽  
Hendri Syamsudin ◽  
Sandro Mihradi
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Laminate Plate ◽  
Maximum Tensile Stress ◽  
Finite Width ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Edge Distance ◽  
Bearing Stress

Stresses were calculated for orthotropic laminate plate loaded by a frictionless pin in a circular hole of the same diameter. These calculations were based on finite-element analysis for five laminates; 00, [±450]s, [00/900]s,[00/±450]s, and quasi-isotropic [00/±450/900]s. stress distribution, based on nominal bearing stress, were determined for wide ranges of the ratios of width to diameter and edge distance to diameter. Orthotropic had a significant influence on both the magnitude and location of the maximum tensile stress concentration on the boundary of the hole. The laminates with 00 plies developed the peak tensile stress near the ends of the pin-hole contact arc. But the ±450 laminates had peaks where ply fiber were tangent to the hole. The finite width and edge distances strongly influenced the tensile stress concentration. In contrast, the finite widths and edge distances had little effect on bearing stress concentration. For the practical range w/d = 2, the peak tensile stresses were as much as 50 percent larger than the infinite-laminate value. For e/d=1, these stresses were greater 60 percent than infinite-laminate value. In contrast, the finite width and edge distance had little effect on bearing stress concentrations.

The preparation of TiO2/SiO2 composite hollow spheres with hydrophobic inner surface and their application in controlled release

2010 ◽  
Vol 45 (10) ◽  
pp. 1351-1356 ◽  
Author(s):  
Li-Feng Yao ◽  
Yan Shi ◽  
Su-Rong Jin ◽  
Mei-Juan Li ◽  
Lian-Meng Zhang
Keyword(s):  
Controlled Release ◽  
Hollow Spheres ◽  
Inner Surface

scholarly journals ANALISIS PENGARUH BENTUK DAN LOKASI BUKAAN PADA BALOK TINGGI MENGGUNAKAN METODE ELEMEN HINGGA

2020 ◽  
Vol 3 (4) ◽  
pp. 1209
Author(s):  
Anthony Fariman ◽  
Leo S. Tedianto
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Wall Structure ◽  
Deep Beam ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Offshore Structure ◽  
Deep Beams ◽  
Concentrated Load ◽  
Cable Networks

ABSTRAKBalok tinggi beton bertulang merupakan salah satu struktur khusus yang dapat memikul beban cukup besar dan umumnya digunakan sebagai transfer girder, struktur lepas pantai, struktur dinding, dan pondasi. Kehadiran bukaan pada balok tinggi dapat memfasilitasi jalur saluran AC, saluran pipa, jaringan kabel dan lain-lain. Dengan adanya bukaan pada balok tinggi dapat memberikan beberapa efek samping yaitu terjadinya diskontinuitas geometri, tegangan terdistribusi non-linier pada balok tinggi, berkurangnya kekuatan dari balok, dan timbulnya konsentrasi tegangan di sekitar bukaan. Penelitian ini bertujuan untuk menganalisis efek dari kehadiran bukaan pada balok tinggi di atas dua perletakan (sendi-rol) dan dibebani beban terpusat di tengah bentang balok lalu memvariasikan bentuk bukaan (persegi, persegi panjang, dan lingkaran) dan lokasi bukaan. Tegangan lentur pada balok tinggi dan konsentrasi tegangan yang terjadi di sekitar bukaan merupakan hal yang akan dibahas dalam penelitian. Analisis akan dibantu dengan Midas FEA yang merupakan program berbasis elemen hingga dan  pemodelan dilakukan dengan elemen solid tiga dimensi. Hasil dari analisis ini menunjukkan bahwa kehadiran bukaan pada balok tinggi menyebabkan kenaikan tegangan secara signifikan. Lokasi dari bukaan yang mendekati daerah tengah bentang balok juga sangat mempengaruhi besarnya tegangan yang terjadi.ABSTRACTReinforced concrete deep beam is one of the special structures that can carry quite a big load and generally used as a transfer girder, offshore structure, wall structure, and foundation. The appearance of openings in deep beams can facilitate AC pipelines, plumbing pipes, cable networks, etc. The existence of openings in deep beams can provide a few side effects such as geometric discontinuity, non-linear stress distributions over the deep beams, reduced strength of the deep beams, and stresses concentration will emerged around the openings. The purpose of this research is to analyze the effects from the existence of openings in deep beams on two supports (hinge and roller) and loaded by concentrated load in mid-span then variate the shape of openings (square, rectangle, and circle) and location of the openings. Flexural stresses in deep beams and the stress concentrations that occur around the openings are discussed in this research. The analysis will be assisted by Midas FEA which is a finite element based program and modelling will be executed in three dimensional solid elements. The result of this analysis showed that the existence of the openings in deep beams can cause stresses to increase significantly high. The location of the openings close to the mid-span of the deep beams also affect the amount of the stresses that occurs.

Effect of Hydrogen on the Fracture Behavior of High-Strength Cr-Mo Steel

2006 ◽  
Vol 512 ◽  
pp. 55-60 ◽  
Author(s):  
Mao Qiu Wang ◽  
Eiji Akiyama ◽  
Kaneaki Tsuzaki
Keyword(s):  
Tensile Stress ◽  
Power Law ◽  
High Strength ◽  
Maximum Tensile Stress ◽  
Maximum Principal Stress ◽  
Slow Strain Rate Test ◽  
Diffusible Hydrogen ◽  
Thermal Desorption Spectrometry ◽  
Stress Concentration Factors ◽  
Peak Value

We examine the hydrogen embrittlement susceptibility of a high-strength AISI 4135 steel by means of a slow strain-rate test (SSRT) using notched round bar specimens. Hydrogen was introduced into the specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS). It was found that the maximum tensile stress decreased in a power law manner with increasing diffusible hydrogen content. Finite element method (FEM) calculations demonstrated that the peak value of the maximum principal stress and the peak value of the locally accumulated hydrogen concentration at the maximum tensile stress were in good agreement with one power law relationship for the specimens with different stress concentration factors.

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