Strain distribution characteristics of welded tube in NC bending process using experimental grid method

2012 ◽  
Vol 66 (5-8) ◽  
pp. 635-644 ◽  
Author(s):  
Ning Ren ◽  
He Yang ◽  
Mei Zhan ◽  
Zhi-Yong Zhang ◽  
Ya-Tao Qin ◽  
...  
Keyword(s):  
Strain Distribution ◽  
Grid Method ◽  
Distribution Characteristics ◽  
Bending Process ◽  
Welded Tube ◽  
Nc Bending

Experimental and numerical studies on the prediction of bendability limit of QSTE340 welded tube in NC bending process

2012 ◽  
Vol 55 (8) ◽  
pp. 2264-2277 ◽  
Author(s):  
He Yang ◽  
Ning Ren ◽  
Mei Zhan ◽  
ZhiYong Zhang ◽  
YaTao Qin ◽  
...  
Keyword(s):  
Numerical Studies ◽  
Bending Process ◽  
Welded Tube ◽  
Nc Bending

Study on 3D Strain Distribution Characteristics Using Etched Grid Method in Tube Bending

2012 ◽  
Vol 184-185 ◽  
pp. 505-509
Author(s):  
Heng Li ◽  
He Yang ◽  
Kai Peng Shi
Keyword(s):  
Strain Distribution ◽  
Three Dimensional ◽  
Grid Method ◽  
Thickness Variation ◽  
Distribution Characteristics ◽  
Tube Bending ◽  
Thickness Strain ◽  
Bending Angle ◽  
Maximum Value ◽  
Wall Thickness Variation

Strain distribution is crucial for understanding tube bending and preventing defects. In this paper, taking 321 stainless steel as the objective, via etched grid method, the strain distribution characteristics during tube bending are studied, the effects of the bending velocity and the bending angle on the strain distribution are analyzed, and the consistency of thickness strain with wall thickness variation is verified. The results show that: (1) three-dimensional (3D) strain is symmetrically distributed about bending plane and reaches the maximum value at wall extrados and intrados; (2) absolute value of the 3D strain increases at first, then decreases in tube bending; (3) compared with bending angle, bending velocity has greater effect on spatial strain, and compared with tangent strain, thickness strain is more sensitive to bending velocity; (4) thickness strain distribution characteristics are generally consistent with distribution characteristics of wall thinning degree.

Strain distribution characteristics of sensing fiber andinfluence on sensitivity of fiber-optic discaccelerometer

2021 ◽  
Author(s):  
Shuaifei Tian ◽  
Haibo Zhu ◽  
Ran An ◽  
Yiping Tang ◽  
yuan yonggui ◽  
...  
Keyword(s):  
Strain Distribution ◽  
Fiber Optic ◽  
Distribution Characteristics

Investigation of Size Effects on Process Models for Plane Strain Microbending

2006 ◽  
Author(s):  
Richard M. Onyancha ◽  
Brad L. Kinsey
Keyword(s):  
Size Effects ◽  
Strain Distribution ◽  
Past Research ◽  
Peak Force ◽  
Process Models ◽  
Analytical Models ◽  
Linear Strain ◽  
Bending Force ◽  
Bending Process ◽  
Individual Grains

Accurate process models provide vital information in the design of manufacturing processes. To characterize bending operations, analytical models have been developed and shown to predict the peak bending forces fairly accurately for sheets in the macro or mesoscale (i.e. sheets with a large number of grains through the thickness). However, whether these models also accurately predict bending forces for sheets in the microscale (i.e. sheets with approximately ten grains or less through the thickness) has not been evaluated. The present study is aimed at investigating the use of two such models from previous work with microscale bending data. In addition, using these previous models as a foundation, additional bending force models were developed to predict the bending force specifically for microscale bending operations. Data analysis showed that the process models from past research, which provide accurate results for macroscale bending, over predict the peak force required for bending microscale sheets. These process models assume a non-linear strain distribution through the thickness and a curved formed wall. The two models developed in this research provide accurate results for the microscale bending tests, however, they under predict the peak force for the macroscale bending operation. These developed process models assume a linear strain distribution through the thickness and a straight formed wall. The linear strain distribution is more appropriate for the microscale bending process as there are few grains through the thickness and the strain in individual grains varies linearly across the grain. The straight formed wall is more appropriate for the microscale bending process as there is not sufficient distance to warrant a curved formed wall assumption. These differences represent size effects for assumptions in the process models. The material used for these investigations was Brass (CuZn15). The sheets had between 2 and 50 grains through the thickness with grain sizes of between 10 μm and 71 μm.

Weld characteristics and NC bending formability of QSTE340 welded tube

2011 ◽  
Vol 17 (4) ◽  
pp. 288-292 ◽  
Author(s):  
Ning Ren ◽  
Mei Zhan ◽  
He Yang ◽  
Yatao Qin ◽  
Zhiyong Zhang ◽  
...  
Keyword(s):  
Welded Tube ◽  
Nc Bending

Numerical Simulation and Experimental Method for Auto-Panel Forming Defects Analysis

2008 ◽  
Vol 575-578 ◽  
pp. 169-173
Author(s):  
Hui Yu Xiang ◽  
Chong Jie Leng ◽  
Yue Xian Zhong
Keyword(s):  
Numerical Method ◽  
Experimental Method ◽  
Strain Distribution ◽  
Grid Method ◽  
Practical Case ◽  
Body Parts ◽  
Forming Process ◽  
Auto Body ◽  
As Stress ◽  
Forming Defects

This paper investigated the forming defects causation and related resolving measures by combining numerical method with experimental technique. A practical case of one auto-body panel stamped parts with forming defects was studied in detail. A new approach determining the causation of forming defects and finding out resolving ways was proposed. Firstly, uses numerical method to analyze the characteristics of the whole forming process by dividing the forming process into virtual steps, so as to obtain the forming feature such as stress & strain distribution during the stamping process. Secondly, uses experimental grid method to measure the real plastic strain distribution of the defective area thus to analyze the forming rule of this area. By synthesizing both methods and carrying out extensive analysis, it is possible to make sure the cause of the defects and put out solving scheme further. The study shows that numerical combined with experimental method is an effective way in analyzing and resolving forming defects for auto-body parts.

Macroscopic collision risk model based on near miss

2021 ◽  
pp. 1-23
Author(s):  
Yangyu Zhou ◽  
Jiaxuan Yang ◽  
Xingpei Bian ◽  
Lingqi Ma ◽  
Zhen Kang
Keyword(s):  
Geographical Distribution ◽  
Risk Model ◽  
Grid Method ◽  
Near Miss ◽  
Distribution Characteristics ◽  
Data Sampling ◽  
Collision Risk ◽  
Model Based ◽  
Marine Traffic ◽  
The Subject

Abstract Using near miss data detected from non-accident information to analyse marine traffic risk can alleviate some of the limitations of accident-based methods. A model based on an arena for detecting scenes of near miss is proposed to detect comprehensively those ship encounters with potential collision risk. To eliminate the influence of data sampling frequency on the detection of scenes of near miss, a single near miss is defined as the whole progress of traffic state from the time the target ship sails into the arena of the subject ship to the time it leaves the arena of the subject ship. To research the geographical distribution characteristics of marine traffic risk, first, a statistical model for the scenes of near miss based on the water grid method is proposed, and then a macroscopic collision risk model based on near miss is developed. The geographical distribution characteristics of marine traffic risk in the Bohai Sea are analysed, and the water areas of high marine traffic risk are obtained. The findings can provide theoretical support for marine safety management.

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