Characteristics Analysis and Optimization of Flying-Wing Vehicle Structure

2014 ◽  
Vol 1077 ◽  
pp. 177-184 ◽  
Author(s):  
Hong Xia Zhou ◽  
Bin Liu
Keyword(s):  
Dynamic Model ◽  
Axial Force ◽  
Structural Characteristics ◽  
Torsional Rigidity ◽  
Bending Rigidity ◽  
Static Test ◽  
Wing Span ◽  
Resonance Test ◽  
Vehicle Structure ◽  
Characteristics Analysis

To study structural characteristics of flying-wing vehicle, static and dynamic model of half wing span, static and dynamic model of all wing span, optimization model were established. Based on associated static test and ground resonance test data, these models were modified to implement static, dynamic and optimization analysis. Results demonstrated that structural bending and torsional deformations are mainly at outer wing surface. Torsion at inner wing is positive, while torsion at outer wing is negative. Total spar axial force along the wing span increases gradually from inner wing to outer wing and then decreases gradually after reaching the inner-outer wing interface. After axial force is transmitted to the inner wing, it is going to concentrate at the rear spar obviously. Structural bending rigidity and torsional rigidity satisfy requirements of both static force and flutter, without flutter problem of main structural mode. Viewed from the optimization size, ±45° and 0° skin at inner-outer wing turn thickens significantly. This can increase structural bending and torsional rigidity, which is good for satisfying multiple constraints comprehensively.

Analytical and experimental analysis of axial force generated by a drive shaft system

2020 ◽  
Vol 234 (4) ◽  
pp. 691-706 ◽  
Author(s):  
Huayuan Feng ◽  
Subhash Rakheja ◽  
Wen-Bin Shangguan
Keyword(s):  
Dynamic Model ◽  
Axial Force ◽  
Friction Model ◽  
Drive Shaft ◽  
Contact Model ◽  
Model Parameters ◽  
Shaft System ◽  
Multibody Dynamic ◽  
Generated Axial Force ◽  
Operational Factors

The drive shaft system with a tripod joint is known to cause lateral vibration in a vehicle due to the axial force generated by various contact pairs of the tripod joint. The magnitude of the generated axial force, however, is related to various operating factors of the drive shaft system in a complex manner. The generated axial force due to a drive shaft system with a tripod joint and a ball joint was experimentally characterized considering ranges of operational factors, namely, the input toque, the shaft rotational speed, the articulation angle, and the friction. The data were analyzed to establish an understanding of the operational factors on the generated axial force. Owing to the observed significant effects of all the factors, a multibody dynamic model of the drive shaft system was formulated for predicting generated axial force under different operating conditions. The model integrated the roller–track contact model and the velocity-based friction model. Based on a quasi-static finite element model, a new methodology was proposed for identifying the roller–track contact model parameters, namely, the contact stiffness and force index. To further enhance the calculation accuracy of the multibody dynamic model, a new methodology for identifying the friction model parameters and the force index was proposed by using the measured data. The validity of the model was demonstrated by comparing the model-predicted and measured magnitudes of generated axial force for the ranges of operating factors considered. The results showed that the generated axial force of the drive shaft system can be calculated more accurately and effectively by using the identified friction and contact parameters in the paper.

Characteristics Analysis of Coir Fiber and Performance Evaluation of Coir Fiberboard

2010 ◽  
Vol 146-147 ◽  
pp. 1549-1552
Author(s):  
Jia Yao ◽  
Ying Cheng Hu ◽  
Wei Lu ◽  
Jin Li
Keyword(s):  
Mechanical Properties ◽  
Nondestructive Testing ◽  
Orthogonal Experiment ◽  
Surface Characteristics ◽  
Dynamic Mechanical Properties ◽  
National Standards ◽  
Coir Fiber ◽  
Static Test ◽  
Characteristics Analysis ◽  
And Performance

SEM observations of coir fiber microstructure have been carried out. Uneven surface characteristics are conducive to the bonding between coir fibers and resin materials. The unique advantages of coir fiber have been verified. Doing orthogonal experiment design for coir fiberboard, the coir fiberboard can meet the mechanical properties of National Standards of China. The various factors optimization plan on the performance of coir fiberboard has been obtained. FFT nondestructive testing has been done for the coir fiberboard. Nondestructive testing results show that the good correlation exists between dynamic mechanical properties and the static test results.

Use of Stochastic Analysis for FMVSS210 Simulation Readiness for Correlation to Hardware Testing

2002 ◽  
Author(s):  
Amit Sharma ◽  
Ashok Deshpande ◽  
Raviraj Nayak
Keyword(s):  
Seat Belt ◽  
Design Sensitivity ◽  
Response Model ◽  
Latin Hypercube Design ◽  
Static Test ◽  
Analytical Simulation ◽  
Vehicle Structure ◽  
Input Parameters ◽  
Explicit Dynamic ◽  
Hardware Test

The FMVSS210 regulation establishes requirements for seat belt assembly anchorages to be strong enough for effective occupant restraint. The belt separation from the vehicle structure in crash tests needs to be avoided. Federal government mandate requires use of Pelvic and Torso Body Blocks for testing belt anchor strengths for lap and shoulder belts respectively. The belt anchorages are expected to withstand loads of 13.34 kN if both lap and shoulder belts are used and 22.24 kN if only lap belts are used. The analytical simulation of the hardware test is done using explicit dynamic code LS-DYNA. Hardware testing is of quasi-static nature while the simulation uses the dynamic code. However the analysis could be made to approach the quasi-static test by adjusting some input parameters in the simulation. In addition some input parameters need adjustment for making the model robust and to make it correlate to the hardware test. This study involves the use of Optimal Symmetnc Latin Hypercube Design to explore the design space, and to develop a fast surface response model. This response model can be viewed as a surrogate model to the actual LS-DYNA simulation and is used in this work to rank the input parameters by the percent contdbution they make towards the variation of the desired output responses. After determining the fit of the response model, it is used to perform the stochastic simulation. The confidence interval for test correlation prediction can then be estimated. This technique can further be used to do design sensitivity studies and for optimizing the vehicle structure with respect to FMVSS210 regulation.

The Optimization Design of Laser Welded Sandwich Plate Structure

2011 ◽  
Vol 418-420 ◽  
pp. 656-659 ◽  
Author(s):  
Yu Ping Sun ◽  
Jin Li ◽  
Zun Li Teng
Keyword(s):  
Optimization Design ◽  
Structural Characteristics ◽  
Optimization Method ◽  
Sandwich Composite ◽  
Optimized Design ◽  
Bending Rigidity ◽  
Bending Performance ◽  
Finite Element Software ◽  
Design Program ◽  
Model Equations

Height lightweight is one of key technology to dock structure that is made up of the sandwich composite board and satisfy requirements of bending rigidity feature. This paper proposes a new engineering optimization method which is both precision and economical. First, through theoretical calculation, to get bending stiffness( , ) and twist stiffness( ). Afterwards ,based on structures bending theory ,we could get the stiffness equation of the model , and calculate the quality equation of the model equations. Supposed the maximal stiffness as objective function ,height(h) of rib and space of rib(a) as design variable.Using MATLAB software and ABAQUS finite element software, we could get the Optimized design program that is to meet the requirements of the structural characteristics of sandwich composite panels of the dock structure. In 100 tons load, when the length of plate is 1m, thickness of plate is 4mm, the height of the rib is 40 mm, the spacing of the rib is 75 mm, and when the height is 45 mm, the spacing is 95 mm, the bending performance of the whole mode lis betterand the quality is more lighter.

scholarly journals Verification of the effect of yarn torsional rigidity on fabric bending rigidity in any direction

2016 ◽  
Vol 87 (4) ◽  
pp. 424-432 ◽  
Author(s):  
Julie Peiffer ◽  
KyoungOk Kim ◽  
Masayuki Takatera
Keyword(s):  
Torsional Rigidity ◽  
Cotton Fabrics ◽  
Bending Rigidity ◽  
Pure Bending ◽  
Experimental Values

The effect of yarn torsional rigidity was verified on the Cooper model for fabric bending rigidity in any direction. We made five cotton fabrics with different weft densities and prepared three commercial fabrics as experimental samples. The torsional rigidity of yarn from the bobbin and that of yarn directly extracted from fabric were measured with a yarn torsional tester. The bending rigidity of yarn from the bobbin was measured using the same pure bending tester as used in fabric bending testing. The bending rigidity of thin fabric was calculated using torsional rigidities of yarns extracted from the fabric and showed better agreement with the experimental values than that calculated using the torsional rigidity of yarn from the bobbin. Indeed, measurements showed that the torsional rigidity of yarn from the bobbin was appreciably higher than the torsional rigidity of yarn from the fabric. This is due to the crimp in the yarn. The fabric bending rigidity can be predicted using the Cooper model with torsional rigidities of yarns extracted from the fabric.

Dynamic Model and Its Characteristics Analysis for Nitrogen Accumulation after Heading in Yongyou 538

2016 ◽  
Vol 42 (4) ◽  
pp. 540 ◽  
Author(s):  
Huan-He WEI ◽  
Tian-Yao MENG ◽  
Chao LI ◽  
Hong-Cheng ZHANG ◽  
Tian-Yu SHI ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Nitrogen Accumulation ◽  
Characteristics Analysis

Dynamic Characteristics Analysis of Supercavitating Vehicle Structure with Stochastic Parameters

2012 ◽  
Vol 430-432 ◽  
pp. 1894-1897
Author(s):  
Yun Hua Jiang ◽  
Wei Guang An ◽  
Hai An
Keyword(s):  
Physical Parameters ◽  
Random Factor ◽  
Supercavitating Vehicle ◽  
Sliding Motion ◽  
Bending Mode ◽  
Stochastic Parameters ◽  
Vehicle Structure ◽  
Frequency Calculation ◽  
Characteristics Analysis ◽  
Calculation Results

Stiffness and mass matrixes were given for frequency calculation of supercavitating vehicle structure (SVS) based on semi-analytical finite element method. Considering the randomicity of physical parameters and their relativity, the function of stochastic frequency and probability density function were obtained for SVS by random factor method. The randomicity of frequency for SVS with stochastic physical parameters was analyzed and the characteristics of probability distribution were given for front five order modes. The calculation results show that SVS is the most prone to bending mode, it’s extremely disadvantage for SVS stability sliding motion in supercavitation. In addition, the frequency have strong randomicity, the external incent frequency in a larger range may lead to load characteristics more bad for SVS.

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