Optimization for Vibration Reduction in Final Phase of Automotive Body Structural Design

2001 ◽  
Author(s):  
Yasuaki Tsurumi ◽  
Toshiaki Nakagawa ◽  
Nobuyuki Mori ◽  
Hiroshi Yamakawa
Keyword(s):  
Structural Design ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Design Method ◽  
Element Model ◽  
Performance Criteria ◽  
Scale Model ◽  
Automotive Body ◽  
Large Scale Model ◽  
Noise Vibration

Abstract In automotive body structural design, Computer Aided Engineering (CAE) has been widely used in order to evaluate noise, vibration, harshness (NVH). A CAE engineer has usually used a large-scale finite element model exceeding 1 million degrees of freedom to improve NVH performance criteria in the final design phase. It is, however, difficult for a CAE engineer to propose the modification candidate for the NVH reduction to an automotive designer in the phase, while good accuracy of the analysis is obtained by using the large-scale model. Only the small modifications can be performed for the NVH performance since configurations of main frame structures are usually determined with respect to crashworthiness in the phase. Therefore, a CAE engineer cannot provide the designer with effective information on time. In this paper, a new optimal design method using a reduction scheme based on the physical coordinates under many design constraints regarding the crashworthiness is proposed in order to overcome above problems. Our proposed method finds out an optimal layout and stiffness value efficiently from the calculation results of the large-scale model. That is, we determine the appropriate location and additional scalar spring constants by minimizing the acceleration of the observation grid. The effectiveness and availability of this method are confirmed using an example.

The Small-Scale Distortion Model Design Method for Ultimate Strength Test of Hull Girder

2014 ◽  
Author(s):  
Chenfeng Li ◽  
Huilong Ren ◽  
Donghao Xu ◽  
Zeng Ji
Keyword(s):  
Large Scale ◽  
Design Method ◽  
Scale Model ◽  
Small Scale ◽  
Model Design ◽  
Hull Girder ◽  
Distortion Model ◽  
Section Modulus ◽  
Large Scale Model ◽  
Ultimate Moment

The objective of this paper is to develop a design method of small-scale distortion model for ultimate bearing capacity test. The ultimate moment is an important index of ship girder strength. Experimental analyses are regarded as the most straightforward and effective methods to predict ultimate moment of hull girder, especially full-scale and/or large-scale model testing. However, large-scale model test not only requires high loading capacity of test device, but it also costs a lot of human and material resources. Based on the similarity theory and failure mechanism of hull girder under bending, a small-scale distortion model design method is presented in this paper. In which, the transverse section is divided into several parts, such as main deck, middle deck, bottom and so on. Then, two similar criterions are required to follow. There are section modulus of each part and critical stress of main stiffened plats. The similar section modulus ensures a similar stress distribution of transverse section between model and real structures under bending; the similar critical stress ensures the same failure modes of stiffened plates. Based on this method, a real vessel is taken as example to design its small-scale (1/25 scale) distortion model. The simulating results indicate that this model design method is precise and reliable.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

Effect of an Oscillating Flow Direction on Leading Edge Heat Transfer

1984 ◽  
Vol 106 (1) ◽  
pp. 222-228 ◽  
Author(s):  
M. L. Marziale ◽  
R. E. Mayle
Keyword(s):  
Heat Transfer ◽  
Strouhal Number ◽  
Large Scale ◽  
Flow Direction ◽  
Leading Edge ◽  
Periodic Variation ◽  
Scale Model ◽  
Transfer Rates ◽  
Large Scale Model ◽  
Turbulence Length

An experimental investigation was conducted to examine the effect of a periodic variation in the angle of attack on heat transfer at the leading edge of a gas turbine blade. A circular cylinder was used as a large-scale model of the leading edge region. The cylinder was placed in a wind tunnel and was oscillated rotationally about its axis. The incident flow Reynolds number and the Strouhal number of oscillation were chosen to model an actual turbine condition. Incident turbulence levels up to 4.9 percent were produced by grids placed upstream of the cylinder. The transfer rate was measured using a mass transfer technique and heat transfer rates inferred from the results. A direct comparison of the unsteady and steady results indicate that the effect is dependent on the Strouhal number, turbulence level, and the turbulence length scale, but that the largest observed effect was only a 10 percent augmentation at the nominal stagnation position.

Large scale model tests on Royal Schelde SES

1989 ◽  
Author(s):  
R. DE GAAIJ ◽  
E. VAN RIETBERGEN ◽  
M. SLEGERS
Keyword(s):  
Large Scale ◽  
Model Tests ◽  
Scale Model ◽  
Large Scale Model

Experimental Study on the Behavior of a Swimming Pool Onboard a Large Passenger Ship

2009 ◽  
Vol 46 (01) ◽  
pp. 27-33
Author(s):  
Pekka Ruponen ◽  
Jerzy Matusiak ◽  
Janne Luukkonen ◽  
Mikko Ilus
Keyword(s):  
Large Scale ◽  
Hydraulic Cylinder ◽  
Operating Conditions ◽  
Swimming Pool ◽  
Scale Model ◽  
Longitudinal Motion ◽  
Sea State ◽  
Passenger Ship ◽  
Large Scale Model ◽  
Computer Controlled

The water in a swimming pool on the top deck of a large passenger ship can be excited to a resonant motion, even in a moderate sea state. The motion of the water in the pool is mainly caused by longitudinal acceleration, resulting from the ship's pitch and surge motions. At resonance, there can be high waves in the pool and splashing of water. In this study the behavior of the Solarium Pool of the Freedom of the Seas was examined in various sea states and operating conditions. The motions of the pool were calculated on the basis of a linear seakeeping method, and the behavior of the water in the pool was studied with experimental model tests. A large-scale model of the pool was constructed and fitted to a purpose-built test bench that could be axially moved by a computer-controlled hydraulic cylinder. Water elevation in the pool was measured, and all tests were video recorded. Different modifications of the pool were tested to improve the behavior of the pool. A strong correlation between the longitudinal motion and the behavior of the water in the pool was found.

Sign in / Sign up

Export Citation Format

Share Document