Experimental and Numerical Investigation on Radial Stiffness of Origami-inspired Tubular Structures

2021 ◽  
pp. 1-30
Author(s):  
Weijun Shen ◽  
Yang Cao ◽  
Xuepeng Jiang ◽  
Zhan Zhang ◽  
Gül E. Okudan Kremer ◽  
...  
Keyword(s):  
Circular Tube ◽  
Weight Ratio ◽  
Design Parameters ◽  
Thin Wall ◽  
Tubular Structures ◽  
Compression Tests ◽  
Element Analysis ◽  
Radial Stiffness ◽  
Paper Folding ◽  
Engineering Problems

Abstract Origami structures, which were inspired by traditional paper folding arts, have been applied for engineering problems for the last two decades. Origami-based thin-wall tubes have been extensively investigated under axial loadings. However, less has been done with radial stiffness as one of the critical mechanical properties of a tubular structure working under lateral loadings. In this study, the radial stiffness of novel thin-wall tubular structures based on origami patterns have been studied with compression tests and finite element analysis (FEA) simulations. The results show that the radial stiffness of an origami-inspired tube can achieve about 27.1 times that of a circular tube with the same circumcircle diameter (100 mm), height (60 mm), and wall-thickness (2 mm). Yoshimura, Kresling, and modified Yoshimura patterns are selected as the basic frames, upon which the influences of different design parameters are tested and discussed. Given that the weight can vary due to different designs, the stiffness-to-weight ratio is also calculated. The origami-inspired tubular structures with superior stiffness performances are obtained and can be extended to crashworthy structures, functional structures, and stiffness enhancement with low structural weight.

Finite Element Analysis of Machining Thin-Wall Parts

2010 ◽  
Vol 458 ◽  
pp. 283-288 ◽  
Author(s):  
R. Izamshah R.A. ◽  
John Mo ◽  
Song Lin Ding
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
End Milling ◽  
Operating Cost ◽  
Weight Ratio ◽  
Milling Process ◽  
Machining Process ◽  
Thin Wall ◽  
Structural Components ◽  
Element Analysis

In an attempt to decrease weight, new commercial and military aircraft are designs with unitised monolithic metal structural components which contains of thinner ribs (i.e., walls) and webs (i.e., floors). Most of the unitised monolithic metal structural components are machined from solid plate or forgings with the start-to-finish weight ratio of 20:1. The resulting thin-walled structure often suffers a deformation which causes a dimensional surface error due to the action of the cutting force generated during the machining process. To alleviate the resulting surface errors, current practices rely on machining through repetitive feeding several times and manual calibration which resulting in long cycle times, low productivity and high operating cost. A finite element analysis (FEA) machining model is developed in this project to specifically predict the distortion or deflection of the part during end milling process. The model aims to provide an input for downstream decision making on error compensation strategy when machining a thin-wall unitised monolithic metal structural components. A set of machining tests have been done in order to validate the accuracy of the model and the results between simulation and experiment are found in a good agreement.

The Pole Design of 500kV Centrifugal Concrete Filled Thin-Wall Steel Tubular Structures

2014 ◽  
Vol 680 ◽  
pp. 175-178
Author(s):  
Yu Zhuo Jia ◽  
Chuan Hui Zhang
Keyword(s):  
Transmission Lines ◽  
Mechanical Performance ◽  
Bending Moment ◽  
Thin Wall ◽  
Tubular Structures ◽  
Double Pole ◽  
Element Analysis ◽  
Long Term Effect ◽  
The Finite Element Analysis

According to the existing specifications, devise door type double pole of 500kV centrifugal concrete filled thin-wall steel tubular structures, and use the finite element analysis software ANSYS to simulate the pole.The results show that the mechanical performance of door type double pole is fine, can bear the maximum bending moment of roots of the pole well.The safety degree in the long term effect under the load is high,can be used in the 500kV transmission lines. In the technical and economic aspect, construction of centrifugal concrete filled thin-wall steel tubular structures pole is convenient,cover an area of an area small,economic and reasonable.

Optimisation of Subsea Tie-In Spools Using Evolutionary Algorithms

2013 ◽  
Author(s):  
Chris Madeley
Keyword(s):  
Evolutionary Algorithms ◽  
Design Method ◽  
Linear Optimization ◽  
Three Dimensional ◽  
Design Parameters ◽  
Element Analysis ◽  
Design Problems ◽  
Engineering Problems ◽  
Optimum Solution ◽  
Pipeline Design

Tie-in spools must be designed to resist a large number of onerous load combinations. These loads include gravitational, temperature, pressure and environmental loads along with various imposed displacements. Additionally, there are several design constraints that must be satisfied. Due to the three-dimensional geometric freedom of the spool there are many possible design scenarios that could be evaluated in the search for the optimum solution. It is the responsibility of the pipeline design engineer to use their own judgment and experience to find the best possible solution within the design period. Traditionally a trial and error design approach is used in an iterative manner. This method is typically slow and labor intensive and can be too focused on one design concept at the expense of others that are potentially superior. On similar engineering problems with many design parameters automated non-linear optimization routines have been shown to be very effective. Specifically, applying evolutionary algorithms is a robust, time-effective and adaptable approach. Such a tool assists the engineer in finding superior design solutions and assists in searching the entire design space. To test this design method, a multi-objective evolutionary algorithm has been applied to two semi-constrained spool design problems. The spool design has been modeled using finite element analysis. First, the algorithm was applied to the optimization of spool geometry for multiple design objectives. Within 24-hours of runtime the algorithm was able to find superior solutions to those found using a traditional iterative approach. Also, the trade-off between conflicting design objectives could be quantified and visualized to enable the designer to select the most appropriate candidate. The second problem evaluated was the placement of supports to mitigate the onset of vortex induced vibration (VIV). The algorithm was again able to quickly find a better solution and quantify the tradeoff between conflicting design objectives. The paper presents the results of this new design process as applied by subsea pipeline engineers to find optimum spool designs.

A Simplified Design Model for Modular Steel Buildings Subject to Vapor Cloud Explosions (VCEs)

2020 ◽  
Vol 14 ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Dynamic Response ◽  
Minimum Cost ◽  
Design Parameters ◽  
Front Wall ◽  
Steel Buildings ◽  
Element Analysis ◽  
Analysis And Design ◽  
Vapor Cloud ◽  
Building Components ◽  
Analytical Expressions

Background: Modular steel buildings (MSB) are extensively used in petrochemical plants and refineries. Limited guidelines are available in the industry for analysis and design of (MSB) subject to accidental vapor cloud explosions (VCEs). Objectives: The paper presents simplified engineering model for modular steel buildings (MSB) subject to accidental vapor cloud explosions (VCEs) that are extensively used in petrochemical plants and refineries. Method: A Single degree of freedom (SDOF) dynamic model is utilized to simulate the dynamic response of primary building components. Analytical expressions are then provided to compute the dynamic load factors (DLF) for critical building elements. Recommended foundation systems are also proposed to install the modular building with minimum cost. Results: Numerical results are presented to illustrate the dynamic response of (MSB) subject to blast loading. It is shown that (DLF)=1.6 is attained at (td/t)=0.4 for front wall (W1) with (td/T)=1.25. For side walls (DLF)=1.41 and is attained at (td/t)=0.6. Conclusions: The paper presented simplified tools for analysis and design of (MSB) subject accidental vapor cloud blast explosions (VCEs). The analytical expressions can be utilized by practitioners to compute the (MSB) response and identify the design parameters. They are simple to use compared to Finite Element Analysis.

scholarly journals Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 881
Author(s):  
Adrian Dubicki ◽  
Izabela Zglobicka ◽  
Krzysztof J. Kurzydłowski
Keyword(s):  
Absorption Capacity ◽  
Compression Tests ◽  
Element Analysis ◽  
Lightweight Structures ◽  
New Energy ◽  
Absorbing Material ◽  
Lightweight Structure ◽  
3D Printed ◽  
Deformation Force ◽  
Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

Strength envelope of granular soil stabilized by multi-axial geogrid in large triaxial tests

2020 ◽  
Vol 57 (3) ◽  
pp. 448-452 ◽  
Author(s):  
A.S. Lees ◽  
J. Clausen
Keyword(s):  
Triaxial Compression ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Failure Envelope ◽  
Element Analysis ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Triaxial Compression Tests ◽  
Properties Of Soil

Conventional methods of characterizing the mechanical properties of soil and geogrid separately are not suited to multi-axial stabilizing geogrid that depends critically on the interaction between soil particles and geogrid. This has been overcome by testing the soil and geogrid product together as one composite material in large specimen triaxial compression tests and fitting a nonlinear failure envelope to the peak failure states. As such, the performance of stabilizing, multi-axial geogrid can be characterized in a measurable way. The failure envelope was adopted in a linear elastic – perfectly plastic constitutive model and implemented into finite element analysis, incorporating a linear variation of enhanced strength with distance from the geogrid plane. This was shown to produce reasonably accurate simulations of triaxial compression tests of both stabilized and nonstabilized specimens at all the confining stresses tested with one set of input parameters for the failure envelope and its variation with distance from the geogrid plane.

Analysis of a Tubular Linear Permanent Magnet Motor for Reciprocating Compressor Applications

2013 ◽  
Vol 448-453 ◽  
pp. 2114-2119 ◽  
Author(s):  
Izzeldin Idris Abdalla ◽  
Taib Ibrahim ◽  
Nursyarizal Mohd Nor
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Outer Radius ◽  
Design Parameters ◽  
Reciprocating Compressor ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Split Ratio ◽  
Single Coil

This paper describes a design optimization to achieve optimal performance of a two novel single-phase short-stroke tubular linear permanent magnet motors (TLPMMs) with rectangular and trapezoidal permanent magnets (PMs) structures. The motors equipped with a quasi-Halbach magnetized moving-magnet armature and slotted stator with a single-slot carrying a single coil. The motors have been developed for reciprocating compressor applications such as household refrigerators. It is observed that the TLPMM efficiency can be optimized with respect to the leading design parameters (dimensional ratios). Furthermore, the influence of mover back iron is investigated and the loss of the motor is computed. Finite element analysis (FEA) is employed for the optimization, and the optimal values of the ratio of the axial length of the radially magnetized magnets to the pole pitch as well as the ratio of the PMs outer radius-to-stator outer radius (split ratio), are identified.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

Benefits of Using Diamond Dies for Cold Alternate Drawing of Magnesium Alloys

2016 ◽  
Vol 716 ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir Stefanov Hristov ◽  
Kazunari Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Wire Drawing ◽  
High Ductility ◽  
Element Analysis ◽  
The Wire ◽  
Shearing Strain ◽  
Drawing Method

In recent years, due to its low density and high strength/weight ratio, magnesium alloy wires has been considered for application in many fields, such as welding, electronics, medical field (for production of stents). But for those purposes, we need to acquire wires with high strength and ductility. For that we purpose we proposed alternate drawing method, which is supposed to highly decrease the shearing strain near the surface of the wire after drawing, by changing the direction of the wire drawing with each pass and thus acquiring high ductility wires.We have done research on the cold alternate drawing of magnesium alloy wires, by conducting wire drawing of several magnesium wires and testing their strength, hardness, structure, surface and also finite element analysis, we have proven the increase of ductility at the expense of some strength.In this research we are looking to further improve the quality of the drawn wires by examining the benefits of using diamond dies over tungsten carbine dies. Using the alternate drawing method reduces the strength of the drawn wires and thus lowering their drawing limit. By using diamond dies we are aiming to decrease the drawing stress and further increase the drawing limit of the alternate drawn wires and also improve the quality of the finishing surface of the wires. With this in mind we are aiming to produce a good quality wire with low diameter, high ductility, high strength and fine wire surface.

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