Evaluation of notch root elasto-plastic stress–strain state for general loadings using an elastic solution

2004 ◽  
Vol 81 (4) ◽  
pp. 313-325 ◽  
Author(s):  
Raju Sethuraman ◽  
S. Viswanadha Gupta
Keyword(s):  
Strain State ◽  
Notch Root ◽  
Elastic Solution ◽  
Stress Strain ◽  
Stress Strain State ◽  
Plastic Stress

Fatigue Life Prediction of Notched Components Based on Multiaxial Local Stress-Strain Approach

2009 ◽  
Author(s):  
Baoxiang Qiu ◽  
Zengliang Gao ◽  
Xiaogui Wang
Keyword(s):  
Strain State ◽  
Notch Root ◽  
Constitutive Relations ◽  
Local Stress ◽  
Cyclic Plasticity ◽  
Multiaxial Stress ◽  
Stress Strain ◽  
Stress Strain State ◽  
Multiaxial Stress State ◽  
Notched Components

A multiaxial local stress-strain approach based on the Armstrong-Frederick type cyclic plasticity theory was proposed to perform the stress analysis and the fatigue analysis on the notched components. A robust cyclic plasticity model was adopted to describe the non-Masing behavior of 16MnR steel. The incremental form of the multiaxial local stress-strain approach was formulated with the incremental constitutive relations and the incremental Neuber’s rule. The multiaxial stress-strain state at the notch root of notched components subjected to proportional and nonproportional loading was predicted by the multiaxial approximate approach. On the basis of the multiaxial local stress-strain state and the Fatemi-Socie criterion, the fatigue lives of the notched components were predicted. The analytical results show that the proposed multiaxial local stress-strain method can describe the multiaxial stress state at the notch root very well, and the predicted fatigue lives correlate well with the experimental data.

scholarly journals Finite element analysis of elastic-plastic state of crack at the interface between infinite plane and circular inclusion

2019 ◽  
pp. 20-23
Author(s):  
V. J. Adlucky ◽  
A. Yu. Hodes ◽  
V. V. Loboda
Keyword(s):  
Strain State ◽  
Circular Inclusion ◽  
Plastic State ◽  
Isotropic Hardening ◽  
Infinite Plane ◽  
Stress Strain ◽  
Elastic Plastic ◽  
Stress Strain State ◽  
Crack Faces ◽  
Plastic Stress

The problem on determining of elastic-plastic stress-strain state of infinite plane with a circular inclusion made from another material and an arc crack at the interface under action of arbitrary mechanical loadings applied at infinity is considered using the FEM approach. The problem is resolved within the framework of contact model for which the possibility of appearance of contact macrozones between crack faces is assumed. The isotropic hardening of materials with bilinear approximation of stress-strain curves is considered. The infinite plane is modeled by square domain whose size is of an order of magnitude greater than inclusion diameter. Contact interaction of crack faces is simulated using gap elements. To obtain the energy release rate the J-integrals are calculated along several closed contours around the crack tips. The comparison of obtained results with available analytical solutions for linear elasticity shows that insignificant differences take place during transformation from pure elastic to elastic-plastic stress-strain state.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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