德尔福英文笔试答案1.doc

德尔福机械类试题：
1,Briefly describe what is blanking(cutting),forming, coining and embossing　in stamping process.
Blanking: the process of cutting the work piece into two or more parts;
Forming: The processes of pressing the work piece into the expected shape;
Coining: the process of pressing the mold into the slab, the patterns or words on the mold will be appeared on the slab;
Embossing: the process of raising a printed image using an inked die on work piece
2, what is metal clading?
Clad the metal with a thin other metal or alloy in order to prevent corrosion and improve wear resistance and reflecting, and so on..
3, what is the purpose of adding glass fiber to thermoplastic material?
Reinforce
4,In contrast with metal and thermoplastic material, which has a higher　coefficient of thermal expansion(CTE).
Composite materials
5,The most suitable material for a integral hinge design(typical plastic　thickness=0.25 to 0.5mm at hinge)
Nylon
6, Can a bending load makes both compressive and tensile stress in a member?
yes
7, What is the design criteria used in plastics catch/snap?
http://bbs.icax.org/forum.php?mod=viewthread&tid=468842&extra=page%3D1&page=1
8,What is FEA?
Finite element analysis
9,Why is natural frequency important in vibration analysis?
Because the frequency of vibration has nothing to do with initial conditions, but the natural characteristic
10,What is the deflection equation of a cantilever beam fixed at one edge?

1,Briefly describe what is blanking(cutting),forming,coining and embossing　in stamping process.
2,What is metal clading?
3,What is the purpose of adding glass fiber to thermoplastic material?
4,In contrast with metal and thermoplastic material,which has a higher　coefficient of thermal expansion(CTE).
5,The most suitable material for a integral hinge design(typical plastic　thickness=0.25 to 0.5mm at hinge)
6,Can a bending load makes both compressive and tensile stress in a member?
7,What is the design criteria used in plastics catch/snap?
8,What is FEA?
9,Why is natural frequency important in vibration analysis?
10,What is the deflection equation of a cantilever beam fixed at one edge?