Penetration Fracture Characteristics of CFRP Curved Laminates

2005 ◽  
Vol 297-300 ◽  
pp. 183-188
Author(s):  
Young Nam Kim ◽  
Young Jea Cho ◽  
Kil Sung Lee ◽  
Kwang Hee Im ◽  
Koung Suk Kim ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
High Strength ◽  
Space Vehicles ◽  
Absorbed Energy ◽  
Laminated Shells ◽  
Fracture Characteristics ◽  
Before And After ◽  
Cfrp Composite ◽  
Strength And Stiffness ◽  
Impact Kinetic Energy

CFRP composite materials widely used as structural materials for airplanes, ships and aero space vehicles because of their high strength and stiffness. This study aims to investigate the effects of curvature and stacking sequence on the penetration characteristics of CFRP laminated shell. They are stacked to [02/902]S, [03/903]S and [02/903/0]S, [0/902/0]S, and their interlaminar numbers are two and four. We are manufactured to composite laminated shells with curvature radii of 100, 150, 200mm and ∞ (flat-plate), respectively. They were cure to the appropriate hardening temperature (130°C) at the vacuum bag of an autoclave. Composite laminated shells of dimensions 100㎜×140㎜ were prepared. The velocity of the steel ball that transversely impacts a specimen was measured both before and after impact by determining the time for the ball to pass two ballistic-screen sensors located at a known distance apart. In general, the kinetic energy after impact-kinetic energy before impact increased in all specimens. Absorbed energy increased as the curvature increased [03/903]S and [02/902]S which is small interlaminar number, was higher than four interlaminar specimen.

Research on strengthening stone arch bridge with CFRP rebars

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kexin Zhang ◽  
Dachao Li ◽  
Xinyuan Shen ◽  
Wenyu Hou ◽  
Yanfeng Li ◽  
...  
Keyword(s):  
High Strength ◽  
Arch Bridge ◽  
Content Type ◽  
Minor Radius ◽  
Reinforced Plastics ◽  
Before And After ◽  
Load Tests ◽  
Structural Surface ◽  
Strength And Stiffness ◽  
Strengthening Method

PurposeThis paper aims to describe carbon fiber reinforced plastics (CFRP) bars as a way to strengthen a 40-year-old stone arch bridge. To investigate effectiveness of the strengthening method, fielding-load tests were carried out before and after strengthening.Design/methodology/approachHigh-strength CFRP bars with minor radius, high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with CFRP bars – including CFRP bars cutting, crack grouting, original structural surface treatment, implant drilling, CFRP bars installation and pouring mortar – was described. Ultimate bearing capacity of the bridge after strengthening was discussed.FindingsThe results of concrete stress and deflection show that the strength and stiffness of the strengthened bridge are improved. The strengthened way with CFRP bars is feasible and effective.Originality/valueThis paper describes CFRP bars as a way to strengthen a 40-year-old stone arch bridge.

In vitro Behaviour of Alumina-Hydroxiapatite Composites Coatings

2018 ◽  
Vol 69 (6) ◽  
pp. 1416-1418
Author(s):  
Alexandru Szabo ◽  
Ilare Bordeasu ◽  
Ion Dragos Utu ◽  
Ion Mitelea
Keyword(s):  
Pure Titanium ◽  
Titanium Substrate ◽  
High Strength ◽  
Biological Properties ◽  
Commercially Pure Titanium ◽  
Hvof Spraying ◽  
Before And After ◽  
Sbf Solution ◽  
Oxygen Fuel

Hydroxyapatite (HA) is a very common material used for biomedical applications. Usually, in order to improve its poor mechanical properties is combined or coated with other high-strength materials.The present paper reports the manufacturing and the biocompatibility behaviour of two different biocomposite coatings consisting of alumina (Al2O3) and hydroxyapatite (HA) using the high velocity oxygen fuel (HVOF) spraying method which were deposited onto the surface of a commercially pure titanium substrate. The biological properties of the Al2O3-HA materials were evaluated by in vitro studies. The morphology of the coatings before and after their immersing in the simulated body fluid (SBF) solution was characterized by scanning electron microscopy (SEM). The results showed an important germination of the biologic hydroxyapatite crystallite on the surface of both coatings.

scholarly journals Materials for Automotive Lightweighting

2019 ◽  
Vol 49 (1) ◽  
pp. 327-359 ◽  
Author(s):  
Alan Taub ◽  
Emmanuel De Moor ◽  
Alan Luo ◽  
David K. Matlock ◽  
John G. Speer ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
New Materials ◽  
Specific Strength ◽  
Advanced High Strength Steels ◽  
Strength And Stiffness ◽  
The Cost

Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.

scholarly journals Sputtering of Neutral Molecules and Molecular Ions From the Adenine Crystal Surface Induced by the UV Picosecond Laser Pulse

1982 ◽  
Vol 1 (1) ◽  
pp. 37-43 ◽  
Author(s):  
V. S. Antonov ◽  
V. S. Letokhov ◽  
Yu. A. Matveyets ◽  
A. N. Shibanov
Keyword(s):  
Laser Radiation ◽  
Kinetic Energy ◽  
Crystal Surface ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Molecular Ions ◽  
Laser Radiation Intensity ◽  
Ion Sputtering ◽  
Absorbed Energy ◽  
Picosecond Laser Pulse

This paper presents the results of observation of sputtering of neutral molecules and ions from the crystal adenine surface induced by fourth-harmonic Nd:YAG laser radiation with a pulse duration of 30 ps. The energy fluence of laser pulses was in the region (1–3) × 10−4 J/cm2. The kinetic energy distribution of the sputtered molecules spreads up to 0.7 eV. The experiment shows that the threshold of adenine molecular ion sputtering is connected with absorbed energy density in upper layers of the crystal surface but not by laser radiation intensity.

scholarly journals Pulsations of blue supergiants before and after helium core ignition

2013 ◽  
Vol 9 (S301) ◽  
pp. 321-324
Author(s):  
Jakub Ostrowski ◽  
Jadwiga Daszyńska-Daszkiewicz
Keyword(s):  
Energy Density ◽  
Kinetic Energy ◽  
Kinetic Energy Density ◽  
Low Degree ◽  
Before And After

AbstractWe present results of pulsation analyses of B-type supergiant models with masses of 14 – 18 M⊙, considering evolutionary stages before and after helium core ignition. Using a non-adiabatic pulsation code, we compute instability domains for low-degree modes. For selected models in these two evolutionary phases, we compare properties of pulsation modes. Significant differences are found in oscillation spectra and the kinetic energy density of pulsation modes.

scholarly journals Tribological Behavior of Laser Textured Hot Stamping Dies

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Andre Shihomatsu ◽  
Sergio Tonini Button ◽  
Iris Bento da Silva
Keyword(s):  
Surface Topography ◽  
High Pressures ◽  
Hot Stamping ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Tests ◽  
Textured Surface ◽  
Laser Texturing ◽  
Stamping Dies ◽  
Before And After

Hot stamping of high strength steels has been continuously developed in the automotive industry to improve mechanical properties and surface quality of stamped components. One of the main challenges faced by researchers and technicians is to improve stamping dies lifetime by reducing the wear caused by high pressures and temperatures present during the process. This paper analyzes the laser texturing of hot stamping dies and discusses how different surfaces textures influence the lubrication and wear mechanisms. To this purpose, experimental tests and numerical simulation were carried out to define the die region to be texturized and to characterize the textured surface topography before and after hot stamping tests with a 3D surface profilometer and scanning electron microscopy. Results showed that laser texturing influences the lubrication at the interface die-hot sheet and improves die lifetime. In this work, the best texture presented dimples with the highest diameter, depth, and spacing, with the surface topography and dimples morphology practically preserved after the hot stamping tests.

Impact Absorbed Energy of Hat Square Column in High Strength Steels

1996 ◽  
Author(s):  
Akihide Yoshitake ◽  
Kentaro Sato ◽  
Tomoyoshi Okita
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Absorbed Energy

scholarly journals Optimization of Drilling Process Parameters Via Taguchi, TOPSIS and RSA Techniques

2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Research Work ◽  
Cutting Speed ◽  
High Strength ◽  
Drilling Process ◽  
Drill Bit ◽  
Influence Of Process Parameters ◽  
Light Trucks ◽  
Cfrp Composite

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.

scholarly journals Biomimetic Composites with Enhanced Toughening Using Silk Inspired Triblock Proteins and Aligned Nanocellulose Reinforcements

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Kristaps Jaudzems ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Beta Sheets ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.<br>

Experimental study on seismic behaviors of beam with concrete-encased steel truss

2018 ◽  
Vol 21 (13) ◽  
pp. 2018-2029
Author(s):  
Xide Zhang ◽  
Zhiheng Deng ◽  
Xiaofang Deng ◽  
Jingwei Ying ◽  
Tao Yang ◽  
...  
Keyword(s):  
High Strength ◽  
Force Model ◽  
Restoring Force ◽  
Restoring Force Model ◽  
Steel Truss ◽  
Different Types ◽  
Energy Dissipation Capacity ◽  
Load Displacement ◽  
Strength And Stiffness ◽  
Seismic Behaviors

To evaluate the ductility and energy dissipation capacity of the beam with concrete-encased steel truss, eight specimens with different types of steel truss, reinforcement ratios, and shear span ratios were tested by low-cyclic loading regime. The results indicated that beams with concrete-encased steel truss performed plumped load–displacement hysteretic loops as well as high strength and stiffness. Moreover, cross-web members improved their seismic behavior more effectively than non-cross-web members. Finally, the restoring force model of concrete-encased steel truss beam is proposed in accordance with the experimental results, which can be used to predict the load–displacement behavior of concrete-encased steel truss beam. The results could also provide a reference for the design and application of concrete-encased steel truss beam in practice.

Sign in / Sign up

Export Citation Format

Share Document