Effect of T-Shape Shoulder Fillet on the Plastic Deformation Properties of SS400 and LYS160 Steel

Shoulder fillets are widely used in the structural optimization design of metal dampers. However, the plastic deformation property of dampers affected by stress concentration, owing to different fillets, has not been explored in-depth. In this study, two typical metal damper materials with different plastic deformation, i.e., ordinary steel SS400 and low-yield-strength steel LYS160, were investigated. The strengthening effect of fillets under different loading is evaluated by comparing the mechanical properties of different fillet heights. Furthermore, the effect of the stress concentration caused by different fillet shapes, based on the failure mode of materials, is discussed. Subsequently, the fatigue degradation effect under the reciprocating shear loading is studied. Based on a series of studies on the deformation properties of fillets in different ductile materials, the basis for the structural optimization design under plastic deformation is provided.

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An Optimization Design Platform for Fir-Tree Root and Groove for Steam Turbine

Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines ◽

10.1115/gt2018-76595 ◽

2018 ◽

Author(s):

Deqi Yu ◽

Xiaojun Zhang ◽

Jiandao Yang ◽

Kai Cheng ◽

Weilin Shu ◽

...

Keyword(s):

Stress Concentration ◽

Steam Turbine ◽

Gas Turbines ◽

High Speed ◽

Optimization Design ◽

Turbine Blades ◽

Local Stress ◽

Optimization Method ◽

Steam Turbines ◽

Geometry Configuration

Fir-tree root and groove profiles are widely used in gas turbine and steam turbine. Normally, the fir-tree root and groove are characterized with straight line, arc or even elliptic fillet and splines, then the parameters of these features were defined as design variables to perform root profile optimization. In ultra-long blades of CCPP and nuclear steam turbines and high-speed blades of industrial steam turbine blades, both the root and groove strength are the key challenges during the design process. Especially, in industrial steam turbines, the geometry of blade is very small but the operation velocity is very high and the blade suffers stress concentration severely. In this paper, two methods for geometry configuration and relevant optimization programs are described. The first one is feature-based using straight lines and arcs to configure the fir-tree root and groove geometry and genetic algorithm for optimization. This method is quite fit for wholly new root and groove design. And the second local optimization method is based on B-splines to configure the geometry where the local stress concentration occurs and the relevant optimization algorithm is used for optimization. Also, several cases are studied as comparison by using the optimization design platform. It can be used not only in steam turbines but also in gas turbines.

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Stress strain state of elastic plate with elliptical cut-out

Izvestiya vysshikh uchebnykh zavedenii. Fizika ◽

10.17223/00213411/63/11/3 ◽

2020 ◽

pp. 3-8

Author(s):

E.E. Deryugin ◽

Keyword(s):

Plastic Deformation ◽

Stress Concentration ◽

Driving Force ◽

Strain State ◽

Mechanical State ◽

Concentration Coefficient ◽

Stress Strain ◽

Crack Driving Force ◽

Stress Strain State ◽

Stress Concentration Coefficient

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.

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Study on the Stability and Structural Optimization of Self-Elevating Platform Pile Foundation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.203.325 ◽

2012 ◽

Vol 203 ◽

pp. 325-328

Author(s):

Xin Jie Chu

Keyword(s):

Stress Concentration ◽

Structural Optimization ◽

Bearing Capacity ◽

Pile Foundation ◽

Reference Value ◽

The Self ◽

Foundation Design ◽

Operation Stability ◽

Soil Foundation ◽

The Stability

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.

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Structural Optimization Design of an Aircraft Metal-Composite Wing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.341-342.519 ◽

2013 ◽

Vol 341-342 ◽

pp. 519-523

Author(s):

Ya Hui Zhang ◽

Ji Hong Zhu ◽

Jun Shuo Li ◽

Wei Hong Zhang

Keyword(s):

Structural Optimization ◽

Optimization Design ◽

Optimization Method ◽

Design Solution ◽

Metal Composite ◽

Concept Design ◽

Obvious Effect ◽

Reinforced Composite ◽

Three Phase ◽

Composite Wing

The problem of metal-composite wing structural optimization is discussed and a strategy is presented. Topology optimization method is applied to provide load transferring path of structure for concept design. Size, shape and other optimization method are used to provide detailed design for individual components. A three-phase optimization method is discussed for fiber reinforced composite laminate skin. Optimal parameters include ply angle, percentage, thickness, layer shape and sequence. The design of laminate for ease of manufacture is based on a set of manufacturing constraints. This paper deals with a total optimal design solution for aileron structure of an aircraft. The result satisfies all the requirements of strength and stability, and has obvious effect of weight loss.

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Structural optimization design for antenna bracket manufactured by selective laser melting

Rapid Prototyping Journal ◽

10.1108/rpj-05-2017-0084 ◽

2018 ◽

Vol 24 (3) ◽

pp. 539-547 ◽

Cited By ~ 3

Author(s):

Zefeng Xiao ◽

Yongqiang Yang ◽

Di Wang ◽

Changhui Song ◽

Yuchao Bai

Keyword(s):

Structural Optimization ◽

Modal Analysis ◽

Selective Laser Melting ◽

Optimization Model ◽

Optimization Design ◽

Analysis Data ◽

Laser Melting ◽

Design Rules ◽

Content Type ◽

Process Characteristics

Purpose This paper aims to summarize design rules based on the process characteristics of selective laser melting (SLM) and structural optimization and apply the design rules in the lightweight design of an aluminum alloy antenna bracket. The design goal is to reduce 30 per cent of the weight while maintaining the stress levels in the original part. Design/methodology/approach To reduce weight as much as possible, the titanium alloy with higher specific strength was selected during the process of optimization. The material distribution of the bracket was improved by the topology optimization design. The redesign for SLM was used to obtain an optimization model, which was more suitable for SLM. The component performance was improved by shape optimization. The modal analysis data of the structural optimization model were compared with those of the stochastic lightweight model to verify the structural optimization model. The scanning data were compared with those of the original model to verify whether the model was suitable for SLM. Findings Structural optimization design for antenna bracket realized the mass decrease of 30.43 per cent and the fundamental frequency increase of 50.18 per cent. The modal analysis data of the stochastic lightweight model and the structural optimization model indicated that the optimization performance of structural optimization method was better than that of the stochastic lightweight method. The comparison results between the scanning data of the forming part and the original data confirmed that the structural optimization design for SLM lightweight component could achieve the desired forming accuracy. Originality/value This paper summarizes geometric constraints in SLM and derives design rules of structural optimization based on the process characteristics of SLM. SLM design rules make structural optimization design more reasonable. The combination of structural optimization design and SLM can improve the performance of lightweight antenna bracket significantly.

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