Tensile Tests on High Strength Steel Q345 Notched Plates with the Moderate Thickness

2010 ◽  
Vol 143-144 ◽  
pp. 1450-1453
Author(s):  
Wan Zhen Wang ◽  
Lan Ying Jiang ◽  
Ren Quan Sun ◽  
Xin Tang Wang
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Fracture Load ◽  
Displacement Curve ◽  
Notch Depth ◽  
Fracture Ductility ◽  
Notch Sharpness ◽  
Load Displacement ◽  
Notch Edge

In order to study fracture mechanics of high strength steel with the moderate thickness, fracture tests were performed on 10 elliptical notched plates with the thickness of 16mm fabricated from high strength steel Q345. The effect of notch sharpness (the ratio of the length of short axis to that of long axis of elliptic notch, b/a) and notch depth (the ratio of the length of long axis of elliptic notch to the width of plate, a/w) on fracture model of high strength steel was examined. Test results show that the first crack initiates at the notch edge. The fracture ductility is low for the specimens with the sharper notch (a smaller ratio b/a), and the point of crack load lies in hardening phase of load-displacement curve. The fracture ductility is high for the specimens with the obtuse notch (a bigger ratio b/a), and the point of fracture load lies in necking phase of load-displacement curve. There is no qualitative relationship of fracture ductility and the notch depth (a/w). The ultimate strength of notched plates is independent of the notch sharpness (b/a) and notch depth (a/w).

Fracture Test on High Strength Steel Plates with Elliptical Hole

2010 ◽  
Vol 44-47 ◽  
pp. 2647-2650
Author(s):  
Wan Zhen Wang ◽  
You Qian Huang ◽  
Ren Quan Su ◽  
Xin Tang Wang
Keyword(s):  
High Strength Steel ◽  
Elliptic Hole ◽  
Elliptical Hole ◽  
High Strength ◽  
Fracture Load ◽  
Displacement Curve ◽  
Notch Depth ◽  
Fracture Ductility ◽  
Notch Sharpness ◽  
Load Displacement

In order to study fracture mechanics of high strength steel with the moderate thickness, fracture tests were performed on 10 plates with elliptical hole fabricated from high strength steel Q345 with the thickness of 16mm. The effect of the notch sharpness (the ratio of the length of short axis to that of long axis of elliptic hole, b/a) and the notch depth (the ratio of the length of long axis of the elliptic hole to the width of plate, 2a/w) on fracture model of high strength steel was examined. Test results show that the first crack initiates at the notch edge. The fracture ductility is lower for the specimens with the sharper notch (a smaller ratio b/a) and the deeper notch (a larger ratio 2a/w), and the point of crack load lies in hardening phase of load-displacement curve. The fracture ductility is higher for the specimens with the obtuse notch (a larger ratio b/a), and the point of fracture load lies in necking phase of load-displacement curve. The ultimate strength of notched plates is independent of the notch sharpness (b/a) and the notch depth (2a/w).

scholarly journals Experimental Investigation into Corrosion Effect on Mechanical Properties of High Strength Steel Bars under Dynamic Loadings

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hui Chen ◽  
Jinjin Zhang ◽  
Jin Yang ◽  
Feilong Ye
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Dynamic Loading ◽  
High Strength Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Reinforcing Steel ◽  
Test Results ◽  
Cross Sectional ◽  
Steel Bars

The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.

Estimation of transverse tensile behavior of Zircaloy pressure tubes using ring-tensile test and finite element analysis

2012 ◽  
Vol 227 (6) ◽  
pp. 1177-1186 ◽  
Author(s):  
MK Samal ◽  
KS Balakrishnan ◽  
J Parashar ◽  
GP Tiwari ◽  
S Anantharaman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Tests ◽  
Tensile Specimen ◽  
Displacement Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Transverse Tensile ◽  
Pressure Tubes ◽  
Load Displacement

Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward. It is due to the presence of combined membrane as well as bending stresses arising in the loaded condition because of the curvature of the specimen. These tubes are manufactured through a complicated process of pilgering and heat treatment and hence, the transverse properties need to be determined in the as-manufactured condition. It may not also be possible to machine small miniaturized specimen in the circumferential direction especially in the irradiated condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A three-dimensional finite element analysis was performed in order to determine the material true stress–strain curve by comparing experimental load–displacement data with those predicted by finite element analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress–strain data as obtained from ring tensile specimen could describe the load–displacement curve of the miniaturized flat tensile specimen very well. However, it was noted that the engineering stress–strain as directly obtained from the experimental load–displacement curves of the ring tensile tests were very different from that of the miniaturized specimen. This important aspect has been resolved in this work through the use of an innovative type of 3-piece loading mandrel.

Development of Evaluation Method for Delamination Strength Between Micro-Sized Materials in MEMS Devices

2006 ◽  
Vol 977 ◽  
Author(s):  
Chiemi Ishiyama ◽  
Junichi Hata ◽  
Satoru Koyama ◽  
Masato Sone ◽  
Yakichi Higo
Keyword(s):  
Shear Stress ◽  
Mechanical Testing ◽  
Evaluation Method ◽  
Maximum Shear Stress ◽  
Testing Machine ◽  
Fracture Load ◽  
Displacement Curve ◽  
Mems Devices ◽  
Si Substrate ◽  
Load Displacement

AbstractEvaluation method for delamination strength of micro-sized materials has been developed using by FEM and measurement of load-displacement curve of micro-sized specimen. This evaluation method is applied to micro-sized cylindrical SU-8 specimens on Si substrate. The maximum shear stress between SU-8 and Si was analyzed with FEM. Fracture load required to delaminate the two materials was examined using a mechanical testing machine for micro-sized materials, which have been developed in our group. The delamination strength was determined from the maximum shear stress and the fracture load.

PULL-OUT PROPERTIES OF GYPSUM BOARD ANCHORS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Yoshinori Kitsutaka ◽  
Fumiya Ikedo
Keyword(s):  
Numerical Model ◽  
Fracture Energy ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Gypsum Board ◽  
Hydraulic Loading ◽  
Pull Out ◽  
Loading System ◽  
Earthquake Load ◽  
Load Displacement

In this study, pull-out properties of various anchors embedded in gypsum board were investigated. Tensile tests for anchors embedded in 200mm square size gypsum board were conducted to measure the load-load displacement curves. Strength of gypsum board was changed for three conditions and twelve kinds of anchors were selected which were ordinary used for gypsum board anchoring. The loading conditions were a monotonous loading and a repeating loading controlled by a servo-controlled hydraulic loading system to achieve accurate measurement. The fracture energy for each anchors were estimated by the analysis of consumed energy calculated by the load-load displacement curve. The effect of the strength of gypsum board and the types of anchors on the pull-out properties of gypsum board anchors was cleared. A numerical model to predict the load-unload curve of pull-out deformation of gypsum board anchors caused by such as the earthquake load was proposed and the validity on the model was proved.

Study on the Dent Resistance of Warm Forming HSS Parts with Free-Form Surface

2013 ◽  
Vol 365-366 ◽  
pp. 1030-1034
Author(s):  
Yu Qin Guo ◽  
Meng Zhao ◽  
Fu Zhu Li ◽  
Wei Chen ◽  
Long Chen
Keyword(s):  
High Strength Steel ◽  
Evaluation System ◽  
High Strength ◽  
Tensile Tests ◽  
Warm Forming ◽  
Free Form ◽  
Process Conditions ◽  
Forming Process ◽  
Resistance Evaluation ◽  
Free Form Surface

Recently, due to the harsh demands for automobile lightweight and safety, more and more attention is focused on the warm forming process of various high strength steel sheet. In the present work, aiming to the formed parts safety problems caused by elevating temperature, take B340/590DP steel as the research object, the dent resistance of the warm-forming parts with free-form surface is studied. Firstly, combing the warm tensile tests under various conditions with the secondary room temperature tensile tests, a secondary yield constitutive model is established for the researched material by the regression analysis method, which reveals the influences of temperature, strain rate and pre-deformation on the secondary yield behaviors. Secondly, based on the plastic deformation theory and the free-form curves and surfaces theory, a dent resistance evaluation system is proposed for the warm-forming high-strength steel parts with free-form surface. Finally, design a dent resistance model experiment, validate the dent resistance of the warm-forming B340/590DP steel specimens, and determine the relevant coefficient value in the proposed dent resistance evaluation system by means of the obtained experiment data. The research results can be used directly to select the reasonable warm-forming process conditions, control and improve the warm-forming parts quality and performances.

scholarly journals General Research on the Process of the Indirect Hot Stamping Ultra-High-Strength Steel

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1658
Author(s):  
Ziming Tang ◽  
Zhengwei Gu ◽  
Xin Li ◽  
Lijuan Zhu ◽  
Hong Xu ◽  
...  
Keyword(s):  
High Strength Steel ◽  
Fe Simulation ◽  
Hot Stamping ◽  
High Strength ◽  
Tensile Tests ◽  
Punch Speed ◽  
Ultra High Strength Steel ◽  
Simulation Results ◽  
Two Stages ◽  
Quenching Time

Aiming at the need for lightweight requirements of the components in the bus, combined with the advantages of the hot stamping ultra-high-strength steel, a new television (TV) bracket was proposed. The finite element (FE) simulation of the beam part in the TV bracket during the indirect hot stamping process was discussed. After two-stages of pre-forming, the blank was in good formability and without visible cracks. According to the FE simulation results, the punch speed, quenching force, and quenching time significantly affected the temperature, microstructure, hardness, and mechanical properties of the beam part during hot stamping. With the increase of the quenching force and quenching time, the martensite fraction of the beam part was increased. For the beam part, the punch speed should be at least 80 mm/s during the forming stage. For complete quenching, the quenching force should be above 1000 kN and quenching time should be up to 10 s. Based on the parameters from the FE simulation, the forming experiment of the beam part was discussed. Microstructure analyses and microhardness tests as well as tensile tests of the hot stamping beam part were performed. The results confirmed that the FE simulation of the beam part was reliable.

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