文摘
英文文摘
Declaraton
CERTIFICATE
LIST OF Symbol
ABBREVIATIONS
Acknowledgement
Chapter 1 General Introduction
Chapter 2 Literature Review
2.1 Introduction
2.2 USDA Quality Grade
2.3 Maturity and ripening
2.3.1 Definition of maturity
2.3.2 Terminology
2.3.3 Characteristics of maturity index
2.3.4 Requirements for maturity indices
2.3.5 Method to determine maturity
2.3.6 Quality issues for melons
2.3.7 Optimal quality
2.3.8 Components of harvest index
2.4 Testing techniques
2.5 Firmness
2.6 Impact
2.7 Sonic vibration
2.8 Elastic and viscoelastic behavior
2.9 Vibration mode shape
2.10 Conclusion
Chapter 3 Finite Element Based Modal Analysis of the Dynamic Behavior of Melons
3.1 Introduction
3.2 Theory and modeling
3.3 Solution approaches
3.3.1 Calculation methods
3.3.2 Eigenvalue and eigenvector extraction
3.4 Simulation model steps
3.5 Summary
Chapter 4 General Materials and Methods
4.1 Introduction
4.2 Materials and methods
4.2.1 Experimental procedure
4.2.2 Plant material
4.2.3 Fruit parameter measurement
4.2.4 Firmness measurement parameter
4.2.5 Experimental setup
4.2.6 Measurement of acoustic response of fruits
4.3 Summary
Chapter 5 Finite Element Modal of Watermelon and its Application
5.1 Introduction
5.2 Methods and materials
5.2.1 Theory and analysis
5.2.2 Experimental setup
5.2.3 Method
5.3 Finite element modeling of ellipsoidal revolution
5.4 Results and discussion
5.4.1 Vibration shape analysis of finite element model
5.4.2 Selected of location and direction of force excitation and measurement sensor
5.5 Conclusions
Chapter 6 Determination of Acoustic Vibration in Watermelon by Finite Element Modeling
6.1 Introduction
6.2 Materials
6.2.1 Fruits
6.2.2 Ball impactor types
6.3 Measurement of acoustic response of watermelons
6.4 Firmness measurement
6.5 Finite element modeling
6.6 Results and discussion
6.6.1 Comparison of FE results with experimental measurements
6.6.2 Mode shape of the watermelon in vibration
6.6.3 Effect of testing location around the equator of the fruit
6.6.4 Relationship between the resonant frequency and firmness
6.6.5 Relationship between the resonant fiequency and Young's modulus
6.6.6 Relationships between the resonant frequency and stiffness factors
6.7 Conclusions
Chapter 7 Quality Evaluation of Watermelon
7.1 Introduction
7.2 Materials and methods
7.2.1 Fruits
7.2.2 Equipments
7.2.3 Measurement of acoustic impulse - response of fruits
7.2.4 Measurement of firmness of fruits
7.3 Theory and analysis
7.4 Results and discussion
7.4.1 Vibration shape analysis of finite element model
7.4.2 Mode shapes of the watermelon in vibration
7.4.3 Comparison of FE with experimental results
7.4.4 Relationship between resonance frequency and watermelon firmness
7.5 Conclusion
Chapter 8 Firmness Evaluation of Melon using its vibration characteristic and finite element analysis
8.1 Introduction
8.2 Materials and methods
8.2.1 Materials
8.2.2 Experimental determination of the spherical resonant frequency
8.2.3 Firmness measurement
8.2.4 Experimental determination of static elastic modulus
8.3 Finite element simulation of the dynamic properties of intact melons
8.4 Results and discussion
8.4.1 Mode shapes of the melon in vibration
8.4.2 Location and direction of force excitation and measurement sensors
8.4.3 Effect of types ofimpactor on natural frequency
8.4.4 Relations among resonant frequency, stiffness factor and firmness
8.4.5 Elastic modulus of different tested layers
8.5 Conclusions
Chapter 9 Main Conclusions
Chapter 10 Bibliography
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