Experimental Study on Mechanical Property of Steel Reinforced Concrete Short Columns of T-Shaped

2007 ◽  
Vol 340-341 ◽  
pp. 1121-1126
Author(s):  
Zhe Li ◽  
Xiao Feng Zhang ◽  
Yan Feng Zhao ◽  
De Fa Wang
Keyword(s):  
Shear Strength ◽  
Mechanical Performance ◽  
Pressure Ratio ◽  
Large Degree ◽  
Seismic Intensity ◽  
Axial Pressure ◽  
Displacement Ductility ◽  
Short Columns ◽  
Test Study ◽  
The Impact

The horizontal press performance of column is deteriorated because of special-shaped section. Moreover, because the antiseismic performance of columns is worse, it is only used in regions where seismic intensity is lower. So the main problem is to enhance the ductility. This test study on mechanical performance has been carried out through fourteen SRCTSSC and RCTSSC. The study focuses on the impact of test axial pressure ratio(nt), hooped reinforcement ratio(ρv), shear span ratio(λ) and steel ratio(ρss) to the shear strength and the antiseismic performance of SRCTSSC. It can be concluded that the shear strength of SRCTSSC is increasing with the increasing of nt and ρss , but the degree of increasing is small when nt is a certainty value, and that the shear strength of SRCTSSC is decreasing with increasing of λ; The shear resistance formula of T-shaped column is derived through tests, the calculated results are in correspondence with those of the tests. It also can be concluded that the hysteretic loops of the SRCTSSC are full and the hysteretic behaviors are improved and that the displacement ductility is increasing with increasing of ρv and ρss , but decreasing with the increasing of nt and the degree of variety in high axial pressure ratio is larger than in low axial pressure ratio. If steel bars are added, the shear strength and displacement ductility of SRCTSSC is increased in a large degree, and the capacity of energy dissipation is also enhanced. This test, for applying the special-shape column to higher intensity region, has the certain instructive significance.

EXPERIMENTAL STUDY ON MECHANICAL PROPERTY OF STEEL REINFORCED CONCRETE L-SHAPED SHORT COLUMNS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5755-5761 ◽  
Author(s):  
ZHE LI ◽  
HAO QIN ◽  
HUI DANG ◽  
HUI LI ◽  
JIAN-SHAN ZHANG
Keyword(s):  
Shear Strength ◽  
Axial Load ◽  
Mechanical Performance ◽  
Load Ratio ◽  
Large Degree ◽  
Seismic Intensity ◽  
Shear Capacity ◽  
Displacement Ductility ◽  
Short Columns ◽  
Axial Load Ratio

The horizontal press performance of column is deteriorated because of its special-shaped section. Moreover, because the antiseismic performance of column is worse, special-shaped column is only used in regions where seismic intensity is lower. So the main problem is to enhance the ductility and shear capacity. This test study on mechanical performance has been carried out through 14 SRCLSSC and 2 RCLSSC. The study focuses on the impacts of test axial load ratio (nt), hooped reinforcement ratio (ρ v ), shear span ratio (λ) and steel ratio (ρ ss ) on the shear strength and the antiseismic performance of SRCLSSC. It can be concluded that the shear strength of SRCLSSC is increasing with the increasing of n t and ρ ss , but the degree of increasing is small when n t is a certainty value, and that the shear strength of SRCLSSC is decreasing with increasing of λ; The shear resistance formula of L-shaped column is derived through tests, the calculated results are in correspondence with those of the tests. It also can be concluded that the hysteretic loops of the SRCLSSC are full and the hysteretic behaviors are improved; the displacement ductility is increasing with increasing of ρv and ρ ss , but decreasing with the increasing of n t ; the degree of variety in high axial load ratio is larger than that in low axial load ratio. If steel bars are added, the shear strength and displacement ductility of SRCLSSC are increased in a large degree.

scholarly journals Axial Impact Load of a Concrete-Filled Steel Tubular Member with Axial Compression Considering the Creep Effect

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3134 ◽  
Author(s):  
Tao Lan ◽  
Guangchong Qin ◽  
Jinzhao Zhuang ◽  
Youdi Wang ◽  
Qian Zheng ◽  
...  
Keyword(s):  
Impact Load ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Pressure Ratio ◽  
Impact Resistance ◽  
Axial Pressure ◽  
Axial Impact ◽  
Creep Effect ◽  
The Impact ◽  
Peak Value

The dynamic loads acting on concrete-filled steel tubular members under axial impacts by rigid bodies were studied herein by FEM. The whole impact process was simulated and the time history of the impact load was obtained. The effects of eight factors on the axial impact load were studied; these factors were the impact speed, mass ratio, axial pressure ratio, steel ratio, slenderness ratio, concrete strength, impact position, and boundary conditions. Besides this, the effects of concrete creep on the impact load were also considered by changing the material parameters of the concrete. The results show that axial impact load changes with time as a triangle. The peak value of impact load increases and the impact resistance improves with the growth of the axial pressure ratio, steel ratio, slenderness ratio, and concrete strength after creep occurs. As the eccentricity of the axial impact acting on a concrete-filled steel tubular member increases, the peak value of the impact load decreases. The enhancement of constraints at both ends of the member can improve the impact resistance. The creep reduction coefficients for the peak axial impact load of a concrete-filled steel tubular member under axial compression and considering the creep effect over 6 months and 30 years are 0.60 and 0.55, respectively. A calculation formula for the peak value of impact load was suggested based on the existing formula, and its accuracy was proved by finite element calculation in this study.

Analysis of the Influence of Different Construction Joints on the Ductility of Cast-in-Place Frame Structure

2021 ◽  
Vol 1020 ◽  
pp. 104-113
Author(s):  
Xi Kang Yan ◽  
Bei Zhang ◽  
Guo Liang Zhao ◽  
Shun Zhang
Keyword(s):  
Pressure Ratio ◽  
Concrete Columns ◽  
Frame Structure ◽  
Axial Pressure ◽  
Treatment Methods ◽  
Displacement Ductility ◽  
Construction Joint ◽  
Construction Joints ◽  
Reversed Cyclic

This article through to the two common cast-in-situ frame structure (casting of a whole, with a construction joint) and 6 root not construction joints under axial pressure ratio through concrete columns of different processing low reversed cyclic loading experiment, study their experimental phenomena, hysteresis curves, displacement ductility, stiffness degradation, thus draw the conclusion: 1, the existence of the construction joint can lead to the decline of ductility of frame structure. 2. When the test axial pressure is relatively low, the presence or absence of construction joints and different treatment methods will obviously affect the ductility of the cast-in-place frame structure. 3. When the test axial pressure is relatively high, the presence or absence of construction joints and different treatment methods will not have a significant impact on the ductility of the cast-in-place frame structure.

Frame Column of the Limit Value of Axial Compression Ratio of

2012 ◽  
Vol 166-169 ◽  
pp. 83-87
Author(s):  
Zhi Neng Tong
Keyword(s):  
Seismic Design ◽  
Compression Ratio ◽  
Pressure Ratio ◽  
Axial Pressure ◽  
Limit Values ◽  
Axial Compression Ratio ◽  
Limit Value ◽  
Current Specification ◽  
Ratio Limit ◽  
The Impact

In the current specification of the pressure ratio limit requirement is not specific, not fully consider the impact of seismic design of frame column ductility of other factors. According to the influencing factors of column ductility analysis, reached standard of axial pressure ratio limit values in most cases are conservative, may be appropriate to do the relaxation adjustment conclusion.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Shear strength model for steel reinforced concrete composite members: Short columns and deep beams

2020 ◽  
Vol 216 ◽  
pp. 110748
Author(s):  
Yicong Xue ◽  
Yong Yang ◽  
Yunlong Yu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Strength Model ◽  
Deep Beams ◽  
Steel Reinforced Concrete ◽  
Short Columns

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

scholarly journals Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests

2021 ◽  
Vol 80 (3) ◽  
pp. 1963-1980
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri
Keyword(s):  
Los Angeles ◽  
Crystal Size ◽  
Grain Shape ◽  
Mechanical Performance ◽  
Pore Space ◽  
Construction Material ◽  
Engineering Properties ◽  
Coarse Grained ◽  
The Impact ◽  
The Relationship

AbstractRock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-Deval tests. It was found that high content of primary minerals in rocks (e.g. quartz and feldspar) is a significant parameter for performance evaluation. Traces of secondary and accessory minerals also affect the performance of rocks, although in many cases it is based on the percentage. Furthermore, some studies showed that the effect of mineralogic composition on mechanical strength is not sufficient to draw final conclusions of mechanical performance; therefore, the impact of other textural characteristics should be considered. The disposition of grain size and crystal size (e.g. as result of lithification) showed that rocks composed of fine-grain textural composition of ≤ 1 mm enhanced fragmentation and wear resistance than medium and coarse grained (≥ 1 mm). The effect of grain shape was based on convex and concave shapes and flat and elongated apexes of tested samples. The equidimensional form descriptor of rocks somehow improved resistance to impact from LA than highly flat and elongated particles. Lastly, the distribution of pore space investigated by means of the saturation method mostly showed moderate (R = 0.50) to strong (R = 0.90) and positive correlations to LA and MD tests.

Effect of toughened polyamide-coated carbon fiber fabric on the mechanical performance and fracture toughness of CFRP

2021 ◽  
pp. 002199832199945
Author(s):  
Jong H Eun ◽  
Bo K Choi ◽  
Sun M Sung ◽  
Min S Kim ◽  
Joon S Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Internal Damage ◽  
Impact Tests ◽  
Flexural Tests ◽  
The Impact

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.

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