scholarly journals Optimized Design of Structure of High-Bending-Rigidity Circular Tube

2021 ◽  
Vol 13 (8) ◽  
pp. 4534
Author(s):  
Shaoying Li ◽  
Zhongquan Qu
Keyword(s):  
Structural Optimization ◽  
Circular Tube ◽  
Structural Parameters ◽  
Optimized Design ◽  
Bending Rigidity ◽  
Circular Tubes ◽  
Bending Load ◽  
Optimization Simulation ◽  
Inner Diameter ◽  
Different Shapes

Circular tubes are widely used in daily life and manufacture under bending load. The structural parameters of a circular tube, such as its wall thickness, number and shapes of ribs, and supporting flanges, are closely related to the tube’s bending rigidity. In this study, a tube with eight ribs and a flange was optimized, in order to obtain the lowest weight, through comprehensive structural optimization. We obtained the optimal structural parameters of the tube and the influence of the structural parameters on the tube’s weight. The structural parameters of tubes with different numbers of ribs were optimized. The tube with different number of ribs had the same inner diameter, bending load, and length as the tube with eight ribs. We conducted an experiment to verify the structural optimization simulation. Different tube sizes were subsequently optimized. The optimized tube with four trapezoidal ribs and a flange reduced the weight by more than 73% while maintaining the same deformation. The weight of the optimized tube with a flange reached a stable value after four trapezoidal ribs were added. When the number of ribs was two, the weight was the largest. The analysis results were consistent with the numerical results. A new AWATR (appropriate width and thickness of ribs can improve the bending rigidity of the tubes) formula was proposed, which can effectively improve the bending rigidity of tubes. Different shapes of tubes were optimized and compared. The optimized tube with four trapezoidal ribs and a flange was the lightest and easy to manufacture.

Transient Critical Heat Fluxes of Subcooled Water Flow Boiling in a SUS304-Circular Tube With Various Twisted-Tape Inserts (Influence of Twist Ratio)

2013 ◽  
Author(s):  
Koichi Hata ◽  
Yasuyuki Shirai ◽  
Suguru Masuzaki
Keyword(s):  
Circular Tube ◽  
Flow Boiling ◽  
Heat Fluxes ◽  
Effective Length ◽  
Twisted Tape ◽  
Circular Tubes ◽  
Twisted Tapes ◽  
Swirl Velocity ◽  
Twist Ratio ◽  
Inner Diameter

The transient critical heat fluxes in SUS304-circular tubes with various twisted-tape inserts are systematically measured for mass velocities (G = 3988 to 13620 kg/m2s), inlet liquid temperatures (Tin = 287.55 to 313.14 K), outlet pressures (Pout = 805.11 to 870.23 kPa) and exponentially increasing heat inputs (Q = Q0exp(t/τ), τ = 28.39 ms to 8.43 s) by the experimental water loop comprised of a multistage canned-type circulation pump controlled by an inverter. The SUS304-circular tube of inner diameter (d = 6 mm), heated length (L = 59.4 mm), effective length (Leff = 49.4 mm), L/d (= 9.9), Leff/d (= 8.23) and wall thickness (δ = 0.5 mm) with average surface roughness (Ra = 3.89 μm) is used in this work. The SUS304 twisted tapes with twist ratios, y [= H/d = (pitch of 180° rotation)/d], of 2.40 and 4.45 are used. The transient critical heat fluxes for SUS304-circular tubes with various twisted-tape inserts are compared with authors’ transient CHF data for the empty SUS304-circular tube and a SUS304-circular tube with twisted-tape of y = 3.37, and the values calculated by authors’ transient CHF correlations for the empty circular tube and the circular tube with twisted-tape insert. The influences of heating rate, twist ratio and swirl velocity on the transient CHF are investigated into details and the widely and precisely predictable correlations of the transient CHF against inlet and outlet subcoolings for the circular tubes with various twisted-tape inserts are given based on the experimental data. The correlations can describe the transient CHFs for SUS304-tubes with various twisted-tape inserts obtained in this work within −27 to 7.9% difference.

The influence of infill density gradient on the mechanical properties of PLA optimized structures by additive manufacturing

2021 ◽  
pp. 146442072110071
Author(s):  
AIL Pais ◽  
C Silva ◽  
MC Marques ◽  
JL Alves ◽  
J Belinha
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Additive Manufacturing ◽  
Structural Optimization ◽  
Meshless Method ◽  
Load Case ◽  
Fused Filament Fabrication ◽  
Ductile Metals ◽  
Four Point Bending ◽  
Bending Load

The aim of this work is the development of a novel framework for structural optimization using bio-inspired remodelling algorithm adapted to additive manufacturing. The fact that polylactic acid (PLA, E = 3145 MPa (Young’s modulus) according to the supplier for parts obtained by injection) shows a similar parameterized behavior with ductile metals, in the sense that both materials are characterized by a bi-linear elastic-plastic law, allows to simulate and prototype parts to be further constructed in ductile metals at a lower cost and then be produced with more expensive fabrication processes. Moreover, cellular materials allow for a significant weight reduction and therefore reduction of production costs. Structural optimization algorithms based on biological phenomena were used to determine the density distribution of the infill density of the specimens. Several simple structures were submitted to distinct complex load cases and analyzed using the mentioned optimization algorithms combined with the finite element method and a meshless method. The surface was divided according to similar density and then converted to stereolitography files and infilled with the gyroid structure at the desired density determined before, using open-source slicing software. Smoothing functions were used to smooth the density field obtained with the remodeling algorithms. The samples were printed with fused filament fabrication technology and submitted to mechanical flexural tests similar to the ones analyzed analytically, namely three- and four-point bending tests. Thus, the factors of analysis were the smoothing parameter and the remodeling method, and the responses evaluated were stiffness, specific stiffness, maximum force, and mass. The experimental results correlated (obtaining accuracy of 35% for the three-point bending load case and 5% for the four-point bending load case) to the numerical results in terms of flexural stiffness and it was found that the complexity of the load case is relevant for the efficiency of the functional gradient. The fused filament fabrication process is still not accurate enough to be able to experimentally compare the results based of finite element method and meshless method analyses.

A Study of the Anchor Effect Based on Structural Parameters of Flexible Pressurized Anchor and Pressure from Surrounding Rock

2011 ◽  
Vol 71-78 ◽  
pp. 4634-4637
Author(s):  
Tian Lin Cui ◽  
Jing Kun Pi ◽  
Yong Hui Liu ◽  
Zhen Hua He
Keyword(s):  
Structural Parameters ◽  
Structural Features ◽  
Surrounding Rock ◽  
Design Parameters ◽  
Optimized Design ◽  
Anchor Effect ◽  
The Finite Element Method ◽  
Anchor System ◽  
New Type ◽  
Stress Relation

In order to optimize the design of flexible pressurized anchor, this paper gives a further analysis on structural features of the new type of flexible pressurized anchor and carries out a contact analysis on anchor system by using the finite element method. It calculates as well as researches the contact stress relation of interactional anchor rod and surrounding rock under the circumstance of anchoring, obtaining the law of all major design parameters of anchor rod structure and pressure from surrounding rock influencing the anchoring performance and arriving at the conclusion that the anchor rod is adapted to various conditions of surrounding rock. They not only serve as important references for optimized design and application of anchor rod, but also provide a basis for the experiment of new type of anchor rod.

In-Plane Bending of Curved Circular Tubes

1968 ◽  
Vol 90 (4) ◽  
pp. 666-670 ◽  
Author(s):  
D. H. Cheng ◽  
H. J. Thailer
Keyword(s):  
Experimental Data ◽  
General Solution ◽  
Compatibility Condition ◽  
Circular Tube ◽  
Series Expansions ◽  
Center Line ◽  
Complementary Energy ◽  
Circular Tubes ◽  
Binomial Expansion ◽  
Plane Bending

A general solution is presented for a thin, curved circular tube under in-plane bending. It includes the solution given by Clark and Reissner as a particular case in which the ratio of the radius of the tube to the radius of its center line is very small. The series expansions satisfy the equilibrium equation for any radius ratio while the compatibility condition is guaranteed by minimizing the complementary energy. The minimization is achieved in the manner of Raileigh-Ritz whereas the evaluation of integrals are facilitated by the use of binomial expansion. Numerical results correlate well with the experimental data. The solution is more rapidly convergent as compared to the existing analytical methods.

On Bending of Curved Circular Tubes

1970 ◽  
Vol 92 (1) ◽  
pp. 62-66 ◽  
Author(s):  
David H. Cheng ◽  
Henry J. Thailer
Keyword(s):  
Stress Distribution ◽  
General Solution ◽  
Circular Tube ◽  
Radius Ratio ◽  
Experimental Results ◽  
Asymptotic Solutions ◽  
Asymptotic Formulas ◽  
Circular Tubes

Based on the improved general solution for a thin, circular tube subjected to in-plane end moments, the effect of the radius ratio on the stress distribution, rigidity, and stress intensification factors is studied. The existing asymptotic solutions are reexamined and modified to reflect the effect of the radius ratio. The modified asymptotic formulas are compared with the existing experimental results.

scholarly journals Multi-Objective Parameter Optimization of Flexible Support System of Optical Mirror

2021 ◽  
Vol 11 (17) ◽  
pp. 8071
Author(s):  
Zujin Jin ◽  
Gang Cheng ◽  
Yusong Pang ◽  
Shichang Xu ◽  
Dunpeng Yuan
Keyword(s):  
Support System ◽  
Structural Parameters ◽  
Control Variable ◽  
Internal Resistance ◽  
Optimized Design ◽  
Force Output ◽  
Multi Objective ◽  
Flexible Support ◽  
Objective Parameter ◽  
The Impact

During the processing of an optical mirror, the performance parameters of the bottom support system would affect the surface forming accuracy of the mirror. The traditional bottom support system has a large unadjustable support stiffness, which increases the difficulty of unloading the impact force generated by the grinding disc. In response to this scenario, a flexible support system (FSS) consisting of 36 support cylinders with beryllium bronze reeds (BBRs) and rolling diaphragms (RDs) as key components is designed. It is necessary to analyze the key components of the support cylinder to reduce its axial movement resistance, ensure a consistent force output of each support point. First, the internal resistance model of a flexible support cylinder is established, and the main factors of internal resistance are then analyzed. Thereafter, the multi-objective structural parameters of the BBR and RD are simulated in ANSYS using the control variable method. The optimal structural parameters of BBR and RD are determined by simulation. Finally, experiments are performed on the RD ultimate pressure, internal resistance of the support cylinder, and consistency of the force output of the FSS. The experimental results show that the support cylinder with the optimized design has good force output consistency, which provides a theoretical basis for the application of FSS in optical mirror processing.

Vacuum Forming Refrigerator Inner Liner Structural Optimization

2011 ◽  
Vol 291-294 ◽  
pp. 1069-1073
Author(s):  
Wen Bin Su ◽  
Xiang Bing Sun ◽  
Tao Li ◽  
Bao Jian Liu
Keyword(s):  
Numerical Simulation ◽  
Structural Optimization ◽  
Structural Parameters ◽  
Forming Process ◽  
Significance Level ◽  
Orthogonal Experiments ◽  
Combination Scheme ◽  
Vacuum Forming ◽  
Validation Experiment

Thickness thinning is the principal quality problem in the vacuum forming process of the refrigerator inner liner. In this paper, the structural parameters of refrigerator inner liner were analyzed based on orthogonal experiments and numerical simulation. Optimized structural parameters combination scheme and the significance level of structural parameters to thickness were obtained by analyzing the results of orthogonal experiments. Validation experiment results shown that the quality of refrigerator inner liner based on the optimized structural parameters combination scheme improved effectively.

scholarly journals Plastic Deformation of Metal Tubes Subjected to Lateral Blast Loads

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Kejian Song ◽  
Yuan Long ◽  
Chong Ji ◽  
Fuyin Gao
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Plastic Flow ◽  
Cross Section ◽  
Circular Tube ◽  
Circular Tubes ◽  
Simply Supported ◽  
Different Dimensions ◽  
Thin Walled ◽  
Wave Induced

When subjected to the dynamic load, the behavior of the structures is complex and makes it difficult to describe the process of the deformation. In the paper, an analytical model is presented to analyze the plastic deformation of the steel circular tubes. The aim of the research is to calculate the deflection and the deformation angle of the tubes. A series of assumptions are made to achieve the objective. During the research, we build a mathematical model for simply supported thin-walled metal tubes with finite length. At a specified distance above the tube, a TNT charge explodes and generates a plastic shock wave. The wave can be seen as uniformly distributed over the upper semicircle of the cross-section. The simplified Tresca yield domain can be used to describe the plastic flow of the circular tube. The yield domain together with the plastic flow law and other assumptions can finally lead to the solving of the deflection. In the end, tubes with different dimensions subjected to blast wave induced by the TNT charge are observed in experiments. Comparison shows that the numerical results agree well with experiment observations.

A preliminary study for evaluation of skirt asymmetric drape

2002 ◽  
Vol 14 (5) ◽  
pp. 286-298 ◽  
Author(s):  
V. Sidabraite ◽  
V. Masteikaite
Keyword(s):  
Objective Evaluation ◽  
Shear Rigidity ◽  
Undesirable Effect ◽  
Bending Rigidity ◽  
Measuring Procedure ◽  
Aesthetic Appearance ◽  
Different Shapes ◽  
Preliminary Study ◽  
Fabric Weight

Undesirable effect of asymmetric drape often occurs when cutting patterns of flared skirt on cross. Out of this reason garment seams twist toward the front or back or folds form different shapes on each side of the garment and this lowers garment aesthetic appearance. The new measuring procedure for asymmetric skirt drape near the side seam, based on bottom traces geometry, was developed in this paper. The experiment with four‐gored skirts of six lightweight fabrics was made. It was found that asymmetric drape depends on combination of grain lines directions of front and back panels of a skirt. There were made general conclusions relating skirt asymmetric drape with various fabric characteristics, such as bending rigidity, extensibility, shear rigidity, fabric weight and drape coefficient in this article. According to developed measuring procedure a final objective evaluation of skirt asymmetric drape rate will be done further.

Research on the 1.06 μm Reflectivity of Subwavelength Surface-Relief Structure via Finite Different Time Domain Method

2009 ◽  
Vol 79-82 ◽  
pp. 1679-1682
Author(s):  
Wen Juan Huang ◽  
Chun Hua Lu ◽  
Wei Min Tan ◽  
Yan Zhang ◽  
Zhong Zi Xu
Keyword(s):  
Electromagnetic Wave ◽  
Time Domain ◽  
Circular Tube ◽  
Structural Parameters ◽  
Fdtd Method ◽  
Hollow Structure ◽  
Outer Diameter ◽  
Incident Wavelength ◽  
Relief Structure ◽  
Finite Different Time Domain

In this paper, setting 1.06 μm Gaussian modulated pulse electromagnetic wave as irradiation sources, the influences of structural parameters on reflectivity are analyzed by finite different time domain (FDTD) method. The results show that the filled factor and height are key factors for circular tube relief structure with non absorption. The optimal height could be set to 0.2 μm, which is one odd time of the ratio of incident wavelength λ and four equivalent refractive index 4N, then the best filled factor is between 0.7 and 0.9, the ratio of inner and outer diameter could be set between 0.4 and 0.6, and the structure period has little significant influence. Compared with cylinder solid structure, it has been discovered that circular tube hollow structure could weaken the backward energy of electromagnetic wave, and it would be more suitable for antireflection structure than solid cylinder structure. Moreover, we design two another circular tube relief structures simulations with different extinction coefficients, it is found that the reflectivities are lower up to 0.00016% than the non absorption one.

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