FEM Stress Analysis and Strength of Adhesive-Rivets Combination Joints Under Tensile Shear Loadings

Author(s):  
Toshiyuki Sawa ◽  
Ryo Nogaito

Stress distributions in adhesive-rivets combination joints under tensile shear loadings are analyzed using a three-dimensional finite element method. The effects of the adherend thickness, the number of rivets and the rivet locations on the stress distributions at the interfaces are examined. Experiments to measure the rupture loads of the joints were carried out. As the results, it was found that the peel stress near the edges of the interfaces decreased as the adherend thickness increased. The maximum value of the maximum principal stresses near the edges of the interfaces decreased as the interval between the two rivets in the longitudinal direction decreased in the case where two rivets were combined. However, small effect of the interval between the two rivets in the lateral direction was found in the case of two rivets. The maximum value of the maximum principal stresses near the edges of the interfaces decreased as the interval between the four rivets in the longitudinal direction decreased and that in the lateral direction increased in the case where four rivets were combined. Discussion on the rupture loads of adhesive-rivets combination joints was made. The rupture loads of the joints increased as the number of rivets increased. The rupture loads of the adhesive-rivets combination joints could be increased more than those of only-riveted joints in the case of two rivets. The rupture loads of adhesive-rivets combination joints were found to be almost the same as those of only-riveted joints in the case of four rivets.

Author(s):  
Toshiyuki Sawa ◽  
Masahiro Sasaki ◽  
Yuya Hirayama

Scarf adhesive joints used in practice. However, the stress distributions and the joints strengths have not yet been fully elucidate. Important issues are how to determine the scarf angle in adherend and how to determine the adhesive properties. In this study, the stress distributions in scarf adhesive joints under static tensile loadings are analyzed using three-dimensional finite-element calculations. In the FEM calculations, the effects of Young's modulus of the adhesive, adhesive thickness, scarf angle of the adherend on the stress distributions at the adhesive interfaces are examined. The maximum principal stresses were calculated at every element at the interfaces. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the adhesive interfaces (z=0, 1/s=1). It is also observed that the maximum value of the stress is the smallest, when the scarf angle is 60 degree. In addition, the joint strength is estimated using the interface stress. For the verification of the FEM calculations, the experiments were carried out to measure the strengths and the strains in the joints under static tensile loadings using strain gauges. Fairly good agreements are observed between the numerical and the measured results concerning the joint strength and the strains.


Author(s):  
Toshiyuki Sawa ◽  
Atsushi Karami

The stress distributions in scarf adhesive joints of dissimilar adherends under static bending moments are analyzed using three-dimensional finite-element calculations. The code employed is ANSYS. In FEM calculations, the effects of Young’s modulus of the adhesive, adhesive thickness, scarf angle of the adherend on the stress distributions at the adhesive interface are examined. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the scarf adhesive interface. It is also observed that the maximum value of the stress is minimum, when the scarf angle is 60 degree. In addition, the joint strength is estimated using the obtained stress distribution. For the verification of the FEM calculations, the experiments were carried out to measure the strengths and the strains in the joints under static bending moments using strain gauges. Fairly good agreements are observed between the numerical and the measured results concerning the joint strength and the strains.


Author(s):  
Yukiya Noshita ◽  
Toshiyuki Sawa ◽  
Yuya Omiya

Stress distributions in CFRP adhesive laminated plates subjected to static and impact out-of-plane loadings are analyzed using a three-dimensional finite-element method (FEM). For establishing an optimum design method of the laminated plates, the effects of some factors are examined. As the results, it is found that the maximum value of the von Mises equivalent stress σ eqv occurs at the edge of the CFRP’s interfaces. The maximum value of interface shear stress r i at CFRP interface decreases as the reinforced Young’s modulus and the thickness increases. However, the maximum value of σ eqv at the adhesive layer decreases as the reinforced Young’s modulus and the thickness decreases. In addition, the maximum value of r i at the CFRP’s interface of lower reinforced laminates under impact loadings shows opposite characteristics to those under static loadings. For verification of the FEM calculations, experiments were carried out to measure the strains at the interfaces and the laminates plates strengths. Concerning strain and strength prediction based on von Mises equivalent stress, fairly good agreements were found between the numerical and the experimental results. The FEM results of impacted strain are in fairly good consistent with the measured results. Discussion is made on the effects of some factors on interface stress distributions.


Author(s):  
Toshiyuki Sawa ◽  
Kohei Ichikawa

The stress variations and stress distributions in stepped-lap adhesive joints of dissimilar adherends under impact tensile loadings were analyzed in elastic range using three-dimensional finite element method. The impact loadings were applied to the lower adherend by dropping a weight. The stress distributions in stepped-lap adhesive joints of dissimilar adherends under static tensile loadings were also analyzed using FEM. The effects of Young’s modulus of the adherends, the adhesive thickness and the number of butted steps of adherents ware examined under both impact and static loadings. As the results, The maximum value of stress σ1 increased as Young’s modulus of the adherends increased for the impact loadings. The maximum value of stress σ1 increased as the numbers of steps in the adherends increased for the static loadings. In addition, the experiments to measure the strain response of joints subjected to impact tensile loadings were carried out using strain gauges. A fairly good agreement was found between the numerical and the measured results concerning the strain responses.


2016 ◽  
Vol 716 ◽  
pp. 566-578 ◽  
Author(s):  
Christian Overhagen ◽  
Paul Josef Mauk

Rolling Models have come a long way from the first empirical relations about forward slip and bite conditions to their current state, which allows local quantities to be calculated in two and three dimensions. In this paper, state-of-the-art of analytical modelling of the rolling process is shown with a fully three-dimensional rolling model for hot and cold strip rolling with stress distributions in the longitudinal, vertical and lateral directions. For this purpose, von Karman’s strip approach is extended to account for the stress gradient in lateral direction, as was already shown in different papers. The stress gradient in the vertical (through-thickness) direction is introduced by a modern implementation of Orowan’s inhomogeneous deformation theory. The local stress distributions are compared to results from Finite-Element Calculations obtained with modern FEM codes. It will be shown, under which circumstances expensive FEM calculations can be replaced by simpler models like the one proposed here, which are more time and cost-effective without a significant loss in result precision. The rolling model is extended with a Finite Element Beam Model for work and backup roll deformation, as well as local work roll flattening and thermal crown for hot rolling. The Effects of those features on stress distribution and exit strip profile are shown for hot and cold rolling.


Author(s):  
J M Kihiu ◽  
G O Rading ◽  
S M Mutuli

A three-dimensional finite element method computer program was developed to establish the elastic-plastic, residual and service stress distributions in thick-walled cylinders with flush and non-protruding plain cross bores under internal pressure. The displacement formulation and eight-noded brick isoparametric elements were used. The incremental theory of plasticity with a 5 per cent yield condition (an element is assumed to have yielded when the effective stress is within 5 per cent of the material yield stress) and von Mises yield criterion were assumed. The frontal solution technique was used. The incipient yield pressure and the pressure resulting in a 0.3 per cent overstrain ratio were established for various cylinder thickness ratios and cross bore-main bore radius ratios. For a thickness ratio of 2.25 and a cross bore-main bore radius ratio of 0.1, the stresses were determined for varying overstrain and an optimum overstrain ratio of 37 per cent was established. To find the accuracy of the results, the more stringent yield condition of 0.5 per cent was also considered. The benefits of autofrettage were presented and alternative autofrettage and yield condition procedures proposed.


Author(s):  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito

Residual stress distribution in an oblique nozzle jointed to a vessel with J-groove welds was analyzed using a three-dimensional finite element method. All welding passes were considered in a 180-degree finite element (FE) model with symmetry. Temperature and stress were modeled for simultaneous bead laying. To determine residual stress distributions at the welds experimentally, a mock-up specimen was manufactured. The analytical results show good agreement with the experimental measurement data, indicating that FE modeling is valid.


Author(s):  
Jingheng Shu ◽  
Xin Xiong ◽  
Desmond YR Chong ◽  
Yang Liu ◽  
Zhan Liu

The study aimed to compare the difference of stress distributions in temporomandibular joints (TMJs) between the patients with mandibular asymmetry and asymptomatic subjects and find the relations between deviated distance and biomechanical stress using three-dimensional finite element method, to give guidance to dentists for correction of mandibular asymmetry. Ten facial symmetric subjects without symptoms of temporomandibular disorders (TMD) and 10 mandibular asymmetric patients were recruited and assigned as the Control and Case group respectively. The FE models of the mandible and maxilla were reconstructed from cone-beam computed tomography (CBCT) images. Muscle forces and boundary conditions were applied to the two groups corresponding to centric and anterior occlusions. The simulation manifested significant differences in stresses of the TMJs between the non-deviated and deviated sides in the Case group under the centric and anterior occlusions. The stresses in the Case group were significantly greater than those in the Control group, especially on the non-deviated side. Besides, there were weak and moderate correlations between the third principal stresses and deviated distances for the patients under centric and anterior occlusions. The excessive stresses in the TMJ of patients with mandibular asymmetry were associated with temporomandibular disorders.


Sign in / Sign up

Export Citation Format

Share Document