Study on Design of Metallic Sandwish Structure and its Mechanical and Thermal Properties

2013 ◽  
Vol 461 ◽  
pp. 85-94
Author(s):  
Rui Qiao ◽  
Ce Guo ◽  
Chun Sheng Zhu ◽  
Zhen Dong Dai ◽  
Xiao Ting Jiang

Based on the microstructure of the beetles elytras cross-section, a bio-inspired metallic structure was designed. The mechanical property and the thermal property of the structure were analyzed with finite element method, and the compressive force-displacement curve and temperature distribution the structure were obtained, respectively. At the same time, the bio-inspired metallic structure sample was made with the material of the stainless steel sheet, and the quasi-static experiment and the thermal experiment of the structure were carried out. Comparing the experimental results with the FEM analysis, the results proved both the accuracy and reliability of FEM. Key words:beetle elytra;microstructure;bio-inspired structure; finite element analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Peida Hao ◽  
Yanping Liu ◽  
Yuanming Du ◽  
Yuefei Zhang

In situ nanoindentation was employed to probe the mechanical properties of individual polycrystalline titania (TiO2) microspheres. The force-displacement curves captured by a hybrid scanning electron microscope/scanning probe microscope (SEM/SPM) system were analyzed based on Hertz’s theory of contact mechanics. However, the deformation mechanisms of the nano/microspheres in the nanoindentation tests are not very clear. Finite element simulation was employed to investigate the deformation of spheres at the nanoscale under the pressure of an AFM tip. Then a revised method for the calculation of Young’s modulus of the microspheres was presented based on the deformation mechanisms of the spheres and Hertz’s theory. Meanwhile, a new force-displacement curve was reproduced by finite element simulation with the new calculation, and it was compared with the curve obtained by the nanoindentation experiment. The results of the comparison show that utilization of this revised model produces more accurate results. The calculated results showed that Young’s modulus of a polycrystalline TiO2microsphere was approximately 30% larger than that of the bulk counterpart.


2012 ◽  
Vol 184-185 ◽  
pp. 218-221
Author(s):  
Si Cong Yuan ◽  
Jing Qiang Shang ◽  
Dong Hong Wang ◽  
Dong Dong Wei ◽  
Chang Xiao

For the high hoisting height, wide using range, tower crane is widely utilized in the architecture construction, while there are some deficiencies in the high rising architecture such as chimney, so the performance can’t exerted. By virtue of computer aided technology, the finite element static analysis of metallic structure of unconventional dedicated tower crane is conducted in this paper, and the figures of stress and displacement are achieved for the two working conditions and two structures. It is proved that the results are satisfied the requirements of stiffness and strength, and also foundation is established for the further analysis.


2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.


2013 ◽  
Vol 718-720 ◽  
pp. 703-708 ◽  
Author(s):  
Yu Du ◽  
Wen Hua Wu ◽  
Qian Jin Yue

Tension of mooring chain is the principle characteristic for mooring system. Tensile value which derived from on-site mooring lines could be used for risk assessment, design evaluation etc. It is hard to obtain underwater tension of mooring chain by traditional method, such as strain gauge, FBG, etc. A new tensile measure method is present based on finite element analysis and shape characteristics of stud-less mooring chain. At first, deformation of stud-less mooring chains is analyzed by finite element method and Ansys software. Then, a design of tension-meter is developed on the basis of the deformation characteristic due to the above FEM analysis. Finally, a model calibrate is designed and tested to prove feasibility of present measurement method.


Author(s):  
Pushpdant Jain ◽  
Mohammed Rajik Khan

Spinal instrumentations have been designed to alleviate lower back pain and stabilize the spinal segments. The present work aims to evaluate the biomechanical effect of the proposed Hybrid Stabilization Device (HSD). Non-linear finite element model of lumbar segment L2-L4 were developed to compare the intact spine (IS) with rigid implant (RI) and hybrid stabilization device. To restrict all directional motion vertebra L4 bottom surface were kept fixed and axial compressive force of 500N with a moment of 10Nm were applied to the top surface of L2 vertebrae. The results of range of motion (ROM), intervertebral disc (IVD) pressure and strains for IVD-23 and IVD-34 were determined for flexion, extension, lateral bending and axial twist. Results demonstrated that ROM of HSD model is higher than RI and lower as compared to IS model. The predicted biomechanical parameters of the present work may be considered before clinical implementations of any implants.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowei Wang ◽  
Yingmin Li ◽  
Weiju Song ◽  
Jun Xu

Based on the stiffness limitations of the midtower in multitower cable-stayed bridges, a new stiffening system (tie-down cables) is proposed in this paper. The sag effects and wind-induced responses can be reduced with the proposed system because tie-down cables are short and aesthetic compared with traditional stiffening cables. The results show that the stiffening effect of tie-down cables is better than that of traditional stiffening cables in controlling the displacement and internal force of the bridge based on a static experiment and finite element analysis. Therefore, the proposed system can greatly improve the overall stiffness of a bridge, and its stiffening effect is better than that of traditional stiffening cables in controlling the displacement and internal force. The results provide a reference for the application of such systems in practical engineering.


2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Mariam Md Ghazaly ◽  
Tawfik Ahmed Yahya ◽  
Aliza Che Amran ◽  
Zulkeflee Abdullah ◽  
Mohd Amran Md Ali ◽  
...  

This paper presents an extensive characterising study of two novel electromagnetic actuators, each with different constructions and characteristics aiming to analyse the behaviour and output characteristics of the two designs. The two actuators are Tubular Linear Reluctance Actuator (TLRA) and Tubular Linear Permanent magnet (TLPM) with Halbach array actuator. The study covered the variation of three parameters, which are the actuator air gap, number of turns and actuator size. A comparative section was also presented for the purpose of comparison. The study concentrated extensively on the two characteristics of both actuators known as output thrust force and working range as they are considered as two main concerns of any actuator design. The simulation was used to show the differences between the two designs in many design aspects such as force, displacement and effects of parameters variations. The applied simulation was performed using 3D Finite-element Ansys software, which is capable of showing the magnetic field distribution in the whole actuator and predicting the strength and length of the output stroke.


Author(s):  
MK Samal ◽  
KS Balakrishnan ◽  
J Parashar ◽  
GP Tiwari ◽  
S Anantharaman

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.


2014 ◽  
Vol 693 ◽  
pp. 293-298 ◽  
Author(s):  
Rastislav Duris

Dynamic behavior of mechanical structures results from complex interactions between applied forces and the stiffness properties of the structure. Currently, many problems of structural dynamic analysis are solved using Finite Element Method (FEM). However, in recent years, the implementation of the Fast Fourier Transform (FFT) in low cost computer-based signal analyzers has provided a powerful tool for acquisition and analysis of vibration data. This article discusses combination of two approaches to structural dynamics testing; the experimental part which is referred to as Experimental Modal Analysis (EMA), respectively the analytical part, which is realized by Finite Element Analysis (FEA). Main goal of the paper is calculation of material properties from experimentally determined modal frequencies.


2012 ◽  
Vol 252 ◽  
pp. 298-301
Author(s):  
Xin Li Bai ◽  
Ying Fang Zhang ◽  
Ya Wei Zhao

The mechanics properties of a certain automobile rear axle shell were studied and a large displacement, large strain elastoplastic finite element analysis was carried out. and the followings were obtained: the load-displacement curve at loading point, elastoplastic strain-load curve at the maximum stress point, elastoplastic stress-load curve in dangerous cross-section, and the yielding load at which the dangerous cross-section overall yield. The results show that elastoplastic finite element simulation results are much closer to the experimental corresponding results. Through optimization design in manufacturing system, the weight of the rear axle shell is greatly reduced as compared with the original design. Optimal design not only saves materials and reduces cost, but also greatly reduces the design time. The calculation results provide the necessary data for automobile rear axle design, strength evaluation and fatigue life estimate.


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