scholarly journals Optimization of Steering System of Forklift Vehicle for Idle Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yuan Shen ◽  
Biao Chu ◽  
DongCai Liu ◽  
Chang’an Zhu
Keyword(s):  
Global Sensitivity Analysis ◽  
Fem Analysis ◽  
Steering System ◽  
Optimization Strategy ◽  
Design Guideline ◽  
Efficient Procedure ◽  
Characteristic Modes ◽  
Idle Vibration ◽  
Vibration Tests ◽  
Engine Excitation

This paper presents an optimal design process for the steering system of a forklift vehicle. An efficient procedure for minimizing the engine-induced idle vibration is developed in this study. Reciprocating unbalance and gas pressure torque as two major sources of engine excitation are studied. Using the field vibration tests and FEM analysis, the cause and characteristics of steering system’s idle vibration are recognized. So as to distribute the characteristic modes based on the optimization strategy, global sensitivity analysis of the main parameters is also carried out to achieve the optimal combination of the optimization factors. Based on all analysis above, some structure modifications for optimization are presented to control the idle vibration. The effectiveness and rationality of the improvements are also verified through experimental prototyping testing. This study also makes it possible to provide a design guideline using CAE (computer aided engineering) analysis for some other objects.

EFFECTIVE DYNAMIC STIFFNESS MODEL AND ITS EFFECTS ON ROBOT SAFETY AND PERFORMANCE

2013 ◽  
Vol 37 (3) ◽  
pp. 395-403
Author(s):  
Dongjun Shin ◽  
Zhan Fan Quek
Keyword(s):  
Dynamic Stiffness ◽  
Joint Stiffness ◽  
Optimization Strategy ◽  
Design Guideline ◽  
Controller Gain ◽  
Stiffness Model ◽  
Effective Dynamic ◽  
Stiffness Characteristics ◽  
And Performance ◽  
The Impact

Due to the limited control bandwidth of pneumatic artificial muscles, joint stiffness characteristics and their effects on safety and performance of human-friendly robots should be considered in the frequency domain. This paper introduces the concept of effective dynamic stiffness and validates its model with the Stanford Safety Robot. Experimental results show that the dynamic stiffness demonstrates limited effects on the impact acceleration given the same impact velocity and controller gain, whereas it significantly affects control performance of position tracking due to pressure-induced non-linearities. A stiffness optimization strategy for safety and performance is discussed as a design guideline of human-friendly robots.

Design Guidelines for Dynamic Stability of Tainter Gates

2017 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Charles W. Knisely ◽  
Tatsuya Oku
Keyword(s):  
Dynamic Stability ◽  
Fem Analysis ◽  
Design Guidelines ◽  
Design Stage ◽  
Actual Structure ◽  
Analysis And Design ◽  
Coupled Mode ◽  
Excited Vibration ◽  
Vibration Tests

To ensure the long-term safe operation of newly constructed Tainter gates, methods of analysis and design criteria are needed in the design stage to assure the dynamic stability of any new Tainter gate. For this purpose, the present study provides a detailed procedure for the dynamic design of Tainter gates that can be applied to preliminary designs by gate engineers to assure the dynamic stability of their gate designs. The dynamic stability of the gate can be determined using the natural vibration characteristics ascertained by finite element method (FEM) analysis, reasonable values of actual structure damping actually measured by the field vibration tests, and theoretical analysis of the coupled-mode self-excited vibration that has been previously established by authors. The procedure and the important points of each step are detailed in an example determination of the dynamic stability of a practical Tainter gate.

Fluidelastic and Vortex Induced Vibration of a Finned Tube Array

2002 ◽  
Author(s):  
Kazuo Hirota ◽  
Tomomichi Nakamura ◽  
Hirohiko Kikuchi ◽  
Kazunori Isozaki ◽  
Hirotaka Kawahara
Keyword(s):  
Heat Exchangers ◽  
Tube Bundle ◽  
Acoustic Resonance ◽  
Finned Tube ◽  
Flow Induced Vibration ◽  
Design Guideline ◽  
Vortex Induced Vibration ◽  
Finned Tubes ◽  
Critical Velocities ◽  
Vibration Tests

Fluidelastic and vortex induced vibration are important problems in operating heat exchangers. Many studies have been conducted to solve the problems. As a result, design guideline has already existed for the flow-induced vibration of a tube bundle. On the other hand, some kinds of heat exchanger use finned tube array in order to improve the efficiency of the heat transfer. For finned tube array, some studies for vortex induced acoustic resonance have been conducted, where Strouhal numbers are obtained. However fluctuating lift coefficients due to vortex are important from the viewpoint of tube vibration. Moreover, critical velocities for fluidelastic vibration are also important. In this study, fluidelastic and vortex induced vibration tests were conducted for a triangular finned tube array. Two different frequencies of the vortex shedding were observed. For this tube array, Strouhal numbers were 0.13–0.15, 0.37–0.39. However vortex induced forces were too weak to excite the finned tubes. For this tube array, averaged Connors’ constant K was 6.8.

Analytical Evaluation of a Seismic Capability of Actual LNG Tank Under Severe Seismic Excitation

2002 ◽  
Author(s):  
Hideyuki Tazuke ◽  
Satoru Yamaguchi ◽  
Hiroshi Akiyama ◽  
Tomoki Sakurai ◽  
Toshio Chiba
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Fem Analysis ◽  
Seismic Excitation ◽  
Analytical Evaluation ◽  
Analysis Methods ◽  
Earthquake Resistant ◽  
Lng Tank ◽  
Vibration Tests

The Hyogoken-Nanbu Earthquake in 1995 has recognized us the importance of the resistance capability against earthquakes on the thermal power plant. In this respect, seismic proving tests on the equipment of the thermal power plant have been planned and carried out. Vibration tests and FEM analysis were performed to demonstrate the earthquake resistant property of the tank. FEM analysis was adopted for analyzing lateral slipping and elephant foot bulge (EFB). To verify the validity of the FEM analysis, the results of tests were compared with those of analysis. Using these analysis methods, we estimate the seismic capability of the LNG tank under severe seismic excitation. As the results, we confirmed that lateral slipping and EFB did not occurred at severe seismic excitation.

An efficient procedure for modelling limited plastic flow

1998 ◽  
Vol 212 (8) ◽  
pp. 731-740 ◽  
Author(s):  
P M Blomerus ◽  
D A Hills
Keyword(s):  
Plastic Material ◽  
Notch Root ◽  
Stress Raiser ◽  
Fem Analysis ◽  
The Finite Element Method ◽  
Field Boundary ◽  
Efficient Procedure ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Good Agreement

A degree of plasticity is often tolerated at stress raising features in severely loaded, nominally elastic, components. Conventionally, the methods available for analysis are the finite element method (FEM) or an approximate notch root plastic strain method. The method introduced here is based on the idea of distributing dislocations to form a perturbation on an elasticity solution to solve the problem for an elastic—perfectly plastic material in transverse plane strain. Specialized kernels are used to satisfy exactly the far field boundary conditions and those at the stress raiser, so that only the small plastic enclave of material need be discretized. The method is seen to follow the incremental nature of the problem and to take into account the stress redistribution in plasticity. The problem of a circular hole under remote tension is solved and good agreement with an FEM analysis of a similar problem is observed.

An Experimental Study of EFB Behavior of Large Model Tank

2002 ◽  
Author(s):  
Hideyuki Tazuke ◽  
Satoru Yamaguchi ◽  
Hiroshi Akiyama ◽  
Tomoki Sakurai ◽  
Toshio Chiba
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Large Scale ◽  
Thermal Power ◽  
Fem Analysis ◽  
Scale Model ◽  
Nonlinear Phenomena ◽  
Large Tank ◽  
Lng Tank ◽  
Vibration Tests

We recognized the importance of the seismic capability against earthquakes of the thermal power plant on the occurrence of the Hyogoken-Nanbu Earthquake in 1995. In this respect, seismic proving tests on the equipment of the thermal power plant had been planned and carried out. Vibration tests and FEM analysis were performed to demonstrate the seismic capability of the equipment. A liquefied natural gas (LNG) tank was selected as one of the subjects. One of the remarkable nonlinear phenomena of an actual large tank was Elephant Foot Bulge (EFB). To investigate the EFB behavior of the tank, vibration test of the large scale model tank and FEM analysis were conducted. Then we estimated EFB behavior of the tank.

Global Sensitivity Analysis of the ATV Design Guideline: Which are the most important inputs for a WWTP design?

2012 ◽  
Vol 2012 (12) ◽  
pp. 4239-4249
Author(s):  
Mansour Talebizadeh ◽  
Cristina Martin ◽  
Marc B. Neumann ◽  
Peter A. Vanrolleghem
Keyword(s):  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Design Guideline ◽  
Global Sensitivity ◽  
Wwtp Design

scholarly journals AN EFFECTIVE HYBRID SUPPORT VECTOR REGRESSION WITH CHAOS-EMBEDDED BIOGEOGRAPHY-BASED OPTIMIZATION STRATEGY FOR PREDICTION OF EARTHQUAKE-TRIGGERED SLOPE DEFORMATIONS

2015 ◽  
Vol XL-1-W5 ◽  
pp. 301-305 ◽  
Author(s):  
A. A. Heidari ◽  
S. S. Mirvahabi ◽  
S. Homayouni
Keyword(s):  
Support Vector Regression ◽  
Health Hazards ◽  
Support Vector ◽  
Optimization Strategy ◽  
Efficient Procedure ◽  
Land Sliding ◽  
Computing Approach

Earthquake can pose earth-shattering health hazards to the natural slops and land infrastructures. One of the chief consequences of the earthquakes can be land sliding, which is instigated by durable shaking. In this research, an efficient procedure is proposed to assist the prediction of earthquake-originated slope displacements (EIDS). New hybrid SVM-CBBO strategy is implemented to predict the EIDS. For this purpose, first, chaos paradigm is combined with initialization of BBO to enhance the diversification and intensification capacity of the conventional BBO optimizer. Then, chaotic BBO is developed as the searching scheme to investigate the best values of SVR parameters. In this paper, it will be confirmed that how the new computing approach is effective in prediction of EIDS. The outcomes affirm that the SVR-BBO strategy with chaos can be employed effectively as a predicting tool for evaluating the EIDS.

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