Transient Behavior of CFRP Tensegrity System in a Suspen dome

In order to establish a conclusive result for the application of carbon fibre reinforced polymer (CFRP) cable as a tensegrity system for a suspen dome, the structural integrity assessment of the system, subjected to transient load, must be considered. This paper gives a preliminary assessment of the dynamic behavior of carbon fibre reinforced polymer cable in a suspen dome in comparison with that of the steel counterpart, using a small model of 4 m span and 0.4 m rise. A commercial finite element software namely ANSYS was used for the structure simulation in respect of the experimental design. The results from the simulation show that the carbon fibre reinforced polymer cable gives a reliable assessment as the steel counterpart. The natural frequencies of CFRP cables are higher than those of steel cables due to the CFRP cables’ high stiffness-to-weight ratio and less curvature under gravity loads. CFRP cables influence the structure with good stiffness which provides good vibration resistance. The results also indicate that from a technical point of view, carbon fibre reinforced polymer cables can perform better than steel cables as tensegrity system for a suspen dome. It is concluded that CFRP cables can be applied to replace steel ones as tensegrity system for a suspen dome

A STUDY ON THE ULTIMATE LOAD BEARING CAPACITY OF CARBON FIBRE REINFORCED POLYMER TENSEGRITY SYSTEM IN A SUSPEN DOME

Structural stability is one of the major factors considered for structural design. The integrity of carbon fiber reinforced polymer as a tensegrity system in a suspen dome is investigated by employing a computational model with a span of 93m. ANSYS software was employed for the investigation. The load-displacement curve of the structure was studied to understand the ultimate load bearing capacity in comparison with steel cable using Newton-Raphson and arc length methods. Parameters such as nodal displacement, stresses on the single reticulated layer and internal forces of the tension members that influence the structures integrity were considered. Results show that despite the antistrophic nature of carbon fiber reinforced polymer it possesses similar characteristics as steel cables

The Effect of Temperature on the Mechanical Performance of Steel and Carbon Fiber Reinforced Polymer (CFRP) Tensegrity System

This paper compares the behavioral pattern of steel and carbon fiber reinforced polymer tensegrity system in a suspen-dome that has a span of 4-m span and a 0.4-m, using the finite element method software – namely ANSYS – to undertake the analysis at various temperature regimes. These comparisons were undertaken in order to validate the performance of carbon fiber reinforced polymer cables. Under cold and hot temperatures, the elastic modulus usually reduces as a result of changes in molecular structure. Previous analysis has shown that carbon fiber reinforced polymer cables are able to resist cold and hot temperatures more than steel cables do as the integrity of steel system begins to deform at high temperatures. However, with their low thermal expansion and esthetic properties, carbon fiber reinforced polymer cables can provide structural stability for a tensegrity system in a suspen dome in regions with high temperature conditions

Probability Model of Corrosion-Induced Cracking Time in Chloride-Contaminated Reinforced Concrete

Corrosion-induced concrete cover cracking caused by chloride ion is an important indication of durability limit state for marine reinforced concrete (RC) structures and can ultimately determine the structural service life. In this paper, considering the random nature of factors affecting the corrosion cracking process, a probabilistic model which expands on the deterministic model of cover cracking time is developed by using Monte Carlo simulation technique. The results showed that the time to corrosion cracking can be modelled by the Weibull distribution. Finally, the probabilistic analysis for the cracking time is applied to an in-site RC bridge girder with four different durability design specifications. It is found that the mean and 90% confidence interval of the cover cracking time will increase with the improvement of durability design level, which means that the difficulty in precise prediction with deterministic model will augment accordingly

Low-cost virtual instrumentation system of an energy-dispersive X-ray spectrometer for a scanning electron microscope

The paper describes an energy-dispersive X-ray spectrometer for a scanning electron microscope (SEM-EDXS). It was constructed using the new architecture of a virtual instrument (VI), which is low-cost, space-saving, fast and flexible way to develop the instrument. Computer-aided teaching (CAT) was used to develop the instrument and operation rather than a traditional instrument technique. The VI was designed using the object-oriented program language C++ and compact programmable logical devices (CPLD). These include spectra collection and processing, quantitative analysis and X-ray-intensity distribution analysis. The procedure is described in detail. The VI system gives an e¡ective and user-friendly human interface for the whole analytical task. Some examples are described

Improvement of performance of ultra-high performance concrete based composite material added with nano materials

Ultra-high performance concrete (UHPC), a kind of composite material characterized by ultra high strength, high toughness and high durability. It has a wide application prospect in engineering practice. But there are some defects in concrete. How to improve strength and toughness of UHPC remains to be the target of researchers. To obtain UHPC with better performance, this study introduced nano-SiO2 and nano-CaCO3 into UHPC. Moreover, hydration heat analysis, X-Ray Diffraction (XRD), mercury intrusion porosimetry (MIP) and nanoindentation tests were used to explore hydration process and microstructure. Double-doped nanomaterials can further enhance various mechanical performances of materials. Nano-SiO2 can promote early progress of cement hydration due to its high reaction activity and C-S-H gel generates when it reacts with cement hydration product Ca(OH)2. Nano-CaCO3 mainly plays the role of crystal nucleus effect and filling effect. Under the combined action of the two, the composite structure is denser, which provides a way to improve the performance of UHPC in practical engineering

Effect of solvation shell structure on thermopower of liquid redox pairs

Recent advancements in thermogalvanic batteries offer a promising route to efficient harvesting of low-grade heat with temperatures below 100 {\deg}C. The thermogalvanic temperature coefficient {\alpha}, usually referred to as effective thermopower, is the key parameter determining the power density and efficiency of thermogalvanic batteries. However, the current understanding of improving {\alpha} of redox pairs remains at the phenomenological level without microscopic insights, and the development of electrolytes with high {\alpha} largely relies on experimental trial and error. This work applies the free energy perturbation method based on molecular dynamics simulations to predict the {\alpha} of the {Fe^{3+}/Fe^{2+}} redox pair in aqueous and acetone solutions. We showed that {\alpha} of the {Fe^{3+}/Fe^{2+}} redox pair can be increased from 1.5{\pm}0.3 mV/K to 4.1{\pm}0.4 mV/K with the increased acetone to water fraction. The predicted {\alpha} of {Fe^{3+}/Fe^{2+}} both in pure water and acetone show excellent agreement with experimental values. By monitoring the fluctuation of dipole orientations in the first solvation shell, we discovered a significant change in the variance of solvent dipole orientation between Fe^{3+} and Fe^{2+}, which can be a microscopic indicator for large magnitudes of {\alpha}. The effect of acetone weight fraction in the mixed acetone-water solvent on the {\alpha} of {Fe^{3+}/Fe^{2+}} is also studied. Acetone molecules are found to intercalate into the first solvation shell of the {Fe^{2+}} ion at high acetone fractions, while this phenomenon is not observed in the solvation shell of the Fe^{3+} ion. Such solvation shell structure change of {Fe^{2+}} ions contributes to the enhanced {\alpha} at high acetone fractions. Our discovery provides atomistic insights into how solvation shell order can be leveraged to develop electrolytes with high thermopower

Static Characteristics Analysis of Cable-stayed Suspension Bridges Using CFRP Cables

Abstract-In the principles of equal cable stiffness and equal cable strength, two cable-stayed suspension bridges using CFRP cables with a main span of 800 meters were established. Threedimensional nonlinear method was taken to analyse the static charasteristis of the bridges in the finished state. Compared with the bridge using steel cables with the same structural arrangement, some conclusions were drawn about the effect of different cable materials on the static charasteristics of large span cable-stayed suspension bridges. Under the condition of same structural arrangement, cable-stayed suspension bridges using different cables show a similar flexural status. In the principle of equal cable stiffness, the CFRP bridge show better performance in strength and stiffness. While in the principle of equal cable strength, CFRP bridge show worse performance