Faculty Profiles - TADA Naoya

1922 Evaluation of Growth of Interface Crack between Solder Ball and Copper

EZAKI Yusuke, TADA Naoya, ANDOU Takahiro, HORI Kazuhiko

The proceedings of the JSME annual meeting 2007 209 - 210 2007

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

Growth of crack on the interface between lead-free solder ball and copper was monitored by means of the direct current potential difference method. The solder balls were jointed on the surface of a plate specimen of pure copper and cyclic tension test was carried out. The change in the potential difference of the solder ball increased with the number of cycles and the interface crack was initiated and grew. The relationship between the increase in the potential difference and the cracked area was evaluated and the results were compared with those obtained by the previous electric field analysis. Both results agreed with each other and this suggests that the interface crack can be monitored by the proposed method.

DOI： 10.1299/jsmemecjo.2007.7.0_209

2440 Evaluation of Static Strain at the Fillet of Cylinder Block and the Effect of Tightening Load by Cylinder Head Bolts

IGUCHI Katsuyuki, TADA Naoya, SHIMIZU Ichiro

The proceedings of the JSME annual meeting 2007 453 - 454 2007

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

The static strain at the fillet of cylinder block was evaluated by the finite element method based on a single model of a cylinder block. The fillet is stress concentration part of a cylinder block that is used internal combustion engine. The strain along the fillet varied depending on the position, which was mainly attributed to the stiffness of the cylinder block and the location of cylinder head bolts. An appropriate range of the tightening force of cylinder head bolts for fixing was also evaluated. The minimum force was determined from the minimum pressure on the head packing not to leak the combustion gas. The maximum force was determined from the maximum static strain at the fillet of cylinder block above which cracks could be initiated. This method can be used for optimum designing of cylinder block.

DOI： 10.1299/jsmemecjo.2007.1.0_453

253 Computational Simulation of Micro- to Mesoscopic Deformation Behavior of Rubber-toughened Semi-crystalline Polymer Blends

UCHIDA Makoto, KITANORI Yoshiharu, TADA Naoya

The Computational Mechanics Conference 2006 ( 19 ) 401 - 402 2006.11

107 Application of direct-current electrical potential difference method to interface damage between solder ball and copper by cyclic loading

ANDOU Takahiro, TADA Naoya

2006 ( 44 ) 13 - 14 2006.2

108 Three-dimentional electrical potential analysis for monitoring interface crack between solder ball and copper by direct-current electrical potential difference method

KAMITANI Toru, TADA Naoya, ANDOU Takahiro

2006 ( 44 ) 15 - 16 2006.2

402 Evaluation of Crystal Orientation of Pure Titanium by Micro Indentation Shape

SHIMIZU Ichiro, TADA Naoya, TERAUCHI Daichi

Proceedings of the 1992 Annual Meeting of JSME/MMD 2006 199 - 200 2006

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

A crystal orientation is one of important factors that affect the mechanical properties of single- and poly-crystalline metals in deformation processes. X-ray diffraction method and electron back scatter diffraction method are the typical ways to identify the crystal orientation of grains. Although these methods are possible to give accurate results, they need relatively expensive instruments and operation trainings. The present study aims to show the possibility to use an indentation shape made on a grain's surface for the identification of it's crystal orientation in polycrystalline titanium, which is hexagonal close-packed crystal structure. The strong correlation between the indention shape and the crystal orientation was found for the grain of pure titanium. The results also show the possibility to evaluate the direction of c-axis to a fairly good accuracy by introduced procedures.

DOI： 10.1299/jsmezairiki.2006.0_199