scholarly journals Experimental study of zone of yield strength on corroded construction steel specimens for reuse

2019 ◽  
Vol 279 ◽  
pp. 02009
Author(s):  
Antonio Shopov ◽  
Borislav Bonev
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Experimental Study ◽  
Yield Strength ◽  
Structural Changes ◽  
Steel Structures ◽  
Strain Diagram ◽  
Lower Yield ◽  
Structural Element ◽  
Lower Yield Strength

Zone of yield strength is a part of stress-strain diagram on steel. In this zone is located an upper and lower yield strength points. These points are important for calculation and design of steel structures elements. When a structural element is corroded, its mechanical properties are changed i.e. changes the geometric characteristics, superficial defects appear and leads to structural changes of material. The facts unambiguously determine that in order to decide whether or not the corrosion element can be reuse, it is necessary to study the material and to determine the new values at the yield strength points. In order to legally make the necessary calculation in sizing and to judge for its reuse. The report studies a zone of yield strength on steel elements with corrosion. Experimental data was obtained, then processed using the stochastic method of processing empirically obtained data, and it was determined with sufficient probability the values to be used for calculation and design in practice.

Mechanical Properties and Morphologies of PP/Co-PP/Talc Composites for Microwave Application

2012 ◽  
Vol 626 ◽  
pp. 711-715 ◽  
Author(s):  
J. Piwsawang ◽  
T. Jinkarn ◽  
Chiravoot Pechyen
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Filler Loading ◽  
Lower Yield ◽  
Elongation At Break ◽  
Compression Load ◽  
Microwave Application ◽  
Lower Yield Strength ◽  
Morphology Development ◽  
Internal Mixer

Unmodified talc fillers were compounded with polypropylene (PP) and copolymer polyethylene (Co-PP) separately in a Brabender plasticorder internal mixer at 180 °C and 50 rpm in order to obtain composites, which contain 040 phr (per 100 part of resin) of filler at 40 phr intervals. The morphology development and the mechanical properties of the composites with reference to filler loading were investigated. In terms of mechanical properties, Youngs modulus and maximum compression load increased, whereas yield strength and elongation at break decreased with the increase in filler loading of PP/Co-PP/Talc composites. The PP/Co-PP exhibited lower yield strength and youngs modulus, and higher elongation at break than talc composites (data not show here). Scanning electron microscopy (SEM) was used to examine the structure of the fracture surface to justify the variation of the measured mechanical properties.

Influence of Inhomogeneous Deformation on Tensile Behavior of Sheets Processed Through Constrained Groove Pressing

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Sunil Kumar ◽  
S. Venkatachalam ◽  
Hariharan Krishnaswamy ◽  
Ravi Kumar Digavalli ◽  
H. S. N. Murthy
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Strain Distribution ◽  
Fe Simulation ◽  
Total Elongation ◽  
Image Correlation ◽  
Lower Yield ◽  
Standard Specimens ◽  
Lower Yield Strength ◽  
Miniature Specimens

Constrained groove pressing (CGP) is a severe plastic deformation technique to produce the ultra-fine grained sheet. The inhomogeneous strain distribution and geometry variation induce differential mechanical properties in the processed sheet. The improved mechanical properties of CGP sheets is due to the composite effect of weak and strong regions formed by geometric and strain inhomogeneities. Weaker regions exhibit large strain, lower yield strength, and higher strain hardening compared to stronger regions. The estimation of mechanical properties is influenced by these defects leading to the difference in the mechanical properties along different orientations. Experimental investigation revealed that the commonly used tensile samples cut perpendicular to the groove orientation exhibit variation in thickness along the gauge length affecting the results from tensile tests. To further understand the effect of geometric variation, a typical CGP specimen was reverse engineered and finite element (FE) simulation was performed using the actual geometry of the CGP processed specimen. The strain distribution from FE simulation was validated experimentally using the digital image correlation data. Based on the numerical and experimental studies, miniature specimens were designed to eliminate the geometric effects from the standard parallel specimen. Miniature parallel specimens showed lower yield strength and total elongation compared to the standard specimens. However, the statistical scatter of total elongation of the miniature specimens was much less than that of the standard specimens, indicating better repeatability. Probably this is the first study to quantify the contribution of composite geometric effect in the mechanical properties of CGP.

The Effect of Si Content on the Mechanical Properties of Rheocast Al Components Using the RHEOMETALTM Process

2008 ◽  
Vol 141-143 ◽  
pp. 779-784 ◽  
Author(s):  
Hai Ping Cao ◽  
Olof Granath ◽  
Magnus Wessen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Lower Yield ◽  
Lower Yield Strength ◽  
The Common ◽  
High Integrity ◽  
Semi Solid ◽  
Si Content

The RHEOMETALTM process is a commercially used semi-solid process for production of high integrity cast components. The process differs from most other semi-solid casting processes in that temperature control is not necessary during processing and large amount of slurry with required solid fraction can be quickly produced. The simplicity of this process has led to a large commercial interest during the last year. This work is based on an investigation regarding the variation of as-cast mechanical properties for secondary Al-Si based alloys (~2.5 % Cu) with a Si content varying from 4.55 to 8.90 % using the RHEOMETALTM process. The purpose was to find the most suitable Al-Si alloy for rheocasting, in comparison with the common HPDC-alloy A380 (EN-AC46000). It was found that lower Si containing alloys exhibited better elongation but slightly lower yield strength. The alloy containing 5.39 wt% Si showed the highest ultimate tensile strength in this investigation. The lower Si containing alloys also demonstrated better feedability in the rheocasting process, which is contrary to what normally is found for normal liquid casting processes. Based on the results in this investigation it is recommended to use an alloy containing about 5-7 wt% Si for rheocasting purposes.

Research of Microstructure and Mechanical Properties of the Cold Rolled Hot-Dip Galvanizing DP450 Steel with Low Carbon and High Chromium

2014 ◽  
Vol 1004-1005 ◽  
pp. 188-192 ◽  
Author(s):  
Yun Han ◽  
Shuang Kuang ◽  
Hua Sai Liu ◽  
Ying Hua Jiang ◽  
Guang Hui Liu
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Polygonal Ferrite ◽  
Low Carbon ◽  
Lower Yield ◽  
Dp Steel ◽  
High Chromium ◽  
Microstructure And Mechanical Properties ◽  
Lower Yield Strength ◽  
Cold Rolled

A new cold rolled hot-dip galvanizing DP450 steel with low carbon and high chromium was designed and effect of the galvanizing processes on the microstructure and mechanical properties was also investigated. At last, it was compared with the referenced DP450 steel which was already produced in industry. The results show that microstructure of the experimental steel consists of regular polygonal ferrite, almost 1% MA island and little bainite. The industrial experimental cold-rolled galvanizing DP steel has excellent combined mechanical properties as follow: yield strength is 306 MPa, tensile strength is 467 MPa and elongation (A80) is 33%. Compared to the referenced steel, the experimental DP450 steel has lower yield strength, better elongation and better forming performance, accordingly.

Effects of Mechanical Properties of Metal Films on The Adhesion Strength of Cr/Polyimide Interfaces

1996 ◽  
Vol 436 ◽  
Author(s):  
Jin Won Choi ◽  
Tae Sung Oh
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Yield Strength ◽  
Peel Strength ◽  
Metal Films ◽  
Rf Plasma ◽  
Lower Yield ◽  
Lower Yield Strength ◽  
Sputter Deposited

AbstractEffects of mechanical properties of Cu/Cr metal films on the peel strength of Cr/PI interfaces have been studied. Cr and Cu thin films were successively sputter-deposited on in-situ RF plasma-treated polyimides, and 20 μm-thick Cu was electroplated. With increasing the yield strength of Cu/Cr films from 156 MPa to 325 MPa, peel strength of Cr/PMDA-ODA and Cr/BPDA-PDA were lowered from 75 g/mam to 57 g/mm and from 69 g/mm to 20 g/mm, respectively. With identical Cu/Cr metal films, lower peel strength was obtained on Cr/BPDA-PDA interfaces, compared to the values of Cr/PMDA-ODA. Peel strength was also decreased more pronouncedly on Cr/BPDA-PDA with increasing the yield strength of Cu/Cr metal films. With T/H (80°C/94% R.H.) exposure, however, peel strength was lowered much more pronouncedly on Cr/PMDA-ODA than on Cr/BPDA-PDA, especially for specimens with Cu/Cr metal films of lower yield strength.

Quantitative Analysis of Pre-Strain Effect on Mechanical Properties of the Austenitic Stainless Steel

2014 ◽  
Author(s):  
Zhiwei Chen ◽  
Caifu Qian ◽  
Guoyi Yang ◽  
Xiang Li
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Tensile Testing ◽  
Control Mode ◽  
Strain Effect ◽  
Strain Control

The test of austenitic stainless steel specimens with strain control mode of pre-strain was carried out. The range of pre-strain is 4%, 5%, 6%, 7%, 8%, 9% and 10% on austenitic stainless steel specimens, then tensile testing of these samples was done and their mechanical properties after pre-strain were gotten. The results show that the pre-strain has little effect on tensile strength, and enhances the yield strength more obviously. According to the experimental data, we get a relational expression of S30408 between the value of yield strength and pre-strain. We can obtain several expressions about different kinds of austenitic stainless steel by this way. It is convenient for designers to get the yield strength of austenitic stainless steel after pre-strain by the value of pre-strain and the above expression.

An Investigation of Adaptive Rubber Bearings

2016 ◽  
Author(s):  
C. S. Tsai ◽  
Hui-Chen Su ◽  
Wen-Chun Huang
Keyword(s):  
Yield Strength ◽  
Lower Yield ◽  
Passive Devices ◽  
Major Benefit ◽  
Lead Rubber Bearings ◽  
Lower Yield Strength ◽  
Multiple Levels ◽  
Materials Used ◽  
Rubber Bearings ◽  
Stiffness And Damping

Proposed in this study are several innovative seismic isolators composed of rubber materials that are called adaptive rubber bearings based on their adaptive characteristics. The materials used in the proposed isolators are free of lead commonly found in lead rubber bearings. The lead material results in a heavy environmental burden as well as lower yield strength and damping due to rising temperature during earthquakes, and thus causes larger displacements than we would expect. The designed mechanisms in the proposed isolators enable these devices to be manufactured relatively easily. They also provide extremely high damping to bearings, which is strongly desired by engineers in practice. The proposed rubber bearings are completely passive devices yet possess adaptive stiffness and adaptive high damping. The change in stiffness and damping is predictable and can be calculated at specifiable and controllable displacement amplitudes. The major benefit of the adaptive characteristics of seismic isolators is that a given system can be optimized separately for multiple performance objects at multiple levels of earthquakes. In this study, mathematical formulations are derived to explain the mechanisms of the proposed devices. Experimental results of high velocity cyclical loadings are also provided to verify the advanced concepts of the proposed devices.

Effect of B2 Phase Transformation on the Mechanical Behavior of CuZr-Based Bulk Metallic Glass Composites

2017 ◽  
Vol 898 ◽  
pp. 672-678
Author(s):  
Ran Wei ◽  
Juan Tao ◽  
Shi Lei Liu ◽  
Guo Wen Sun ◽  
Shuai Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Lower Yield ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites ◽  
Lower Yield Strength ◽  
B2 Phase

The mechanical behavior of CuZr-based bulk metallic glass composites with different B2-CuZr phase transformation ability was investigated. The B2 phase transformation is conducive to enhance the mechanical properties of CuZr-based bulk metallic glass composites. The mechanical properties of the austenitic B2 phase specimens were also studied to understand the mechanism of phase transformation effect. It was found that the B2 phase with martensitic transformation exhibits lower yield strength and stronger work-hardening capability than the B2 phase without martensitic transformation. Thus, the phase transformation effect of B2-CuZr phase, accompanying with its lower yield strength and stronger work-hardening capability, is the main reason for the CuZr-based bulk metallic glass composites possess outstanding mechanical properties.

A work-hardening model of the lower yield strength of discontinuously yielding alloys: Ni3Al and mild steel

1989 ◽  
Vol 4 (3) ◽  
pp. 470-472 ◽  
Author(s):  
E. M. Schulson
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Mild Steel ◽  
Work Hardening ◽  
Lower Yield ◽  
Hardening Model ◽  
Lower Yield Strength ◽  
Work Hardening Model ◽  
Lüders Bands

The lower yield strengths of Ni3Al and mild steel and their respective relationships to (grain size)−0.8 and (grain size)−0.5 are explained in terms of work hardening within Lüders bands.

Grain Size Dependence of Tensile Properties in Cu-Sn Thin Foils (Experimental Study)

2015 ◽  
Vol 736 ◽  
pp. 19-23
Author(s):  
Taek Kyun Jung ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Study ◽  
Grain Size ◽  
Yield Strength ◽  
Room Temperature ◽  
Size Dependence ◽  
Yield Drop ◽  
Thin Foils ◽  
Vacuum Atmosphere

This study was carried out to investigate the effects of grain size on mechanical properties in Cu-Sn foil with a thickness of 30 um. The grain size was varied from approximately 7 um to 50 um using heat treatment at 773 K for 2 h to 24 h in a vacuum atmosphere. Tensile test was carried out at room temperature with strain rate of 1mm/min. Typical yield drop phenomenon was observed. Mechanical properties were found to be strongly affected by microstructural features including grain size. The yield strength and tensile strength gradually decreased with increasing the grain size. The strain to fracture also decreased by grain growth. These results could be explained by not only the grain size dependence of yield strength but also the ratio of thickness to grain size dependence of yield strength.

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