Optimization of a Ceramic Circuit Board Clamp

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000394-000401
Author(s):  
David A. Glowka ◽  
Randy A. Normann
Keyword(s):  
Thermal Expansion ◽  
Fixed Point ◽  
Elevated Temperature ◽  
Design Optimization ◽  
Parametric Study ◽  
Material Selection ◽  
Circuit Board ◽  
Differential Thermal Expansion ◽  
Logging Tool ◽  
Clamping Pressure

This paper documents the design optimization of a board-mounting system for securing a ceramic or other heavy circuit board to the electronics chassis in a wireline logging tool. A clamp fixes the extreme lower end of the circuit board to the chassis while allowing the board and chassis to undergo differential thermal expansion above that fixed point, through the use of sliding board mounts. After developing equations that describe the stress, deflection, and thermal expansion of the clamp/board assembly, they are used to select the geometry and material options available in the design. Results of a parametric study are presented that demonstrate how material selection determines whether the clamping pressure on the circuit board improves or degrades at elevated temperature, and how the geometries of the clamp components affect the magnitudes of the forces, deflections, and setting torque of the clamp.

scholarly journals Design optimization of multifunctional metamaterials with tunable thermal expansion and phononic bandgap

2021 ◽  
pp. 109990
Author(s):  
Xing Zhang ◽  
Hongling Ye ◽  
Nan Wei ◽  
Ran Tao ◽  
Zhen Luo
Keyword(s):  
Thermal Expansion ◽  
Design Optimization

Design-optimization and material selection for a femoral-fracture fixation-plate implant

2010 ◽  
Vol 31 (7) ◽  
pp. 3463-3473 ◽  
Author(s):  
M. Grujicic ◽  
G. Arakere ◽  
X. Xie ◽  
M. LaBerge ◽  
A. Grujicic ◽  
...  
Keyword(s):  
Design Optimization ◽  
Fracture Fixation ◽  
Femoral Fracture ◽  
Material Selection ◽  
Fixation Plate ◽  
Selection For

Bilayer graded Al/B4C/rice husk ash composite: Wettability behavior, thermo-mechanical, and electrical properties

2018 ◽  
Vol 52 (27) ◽  
pp. 3745-3758 ◽  
Author(s):  
Amin Bahrami ◽  
Niloofar Soltani ◽  
Martin I Pech-Canul ◽  
Shaghayegh Soltani ◽  
Luis A González ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Aluminum Alloys ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Material Selection ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Expansion Coefficients ◽  
One Step ◽  
The Difference

In this study, wettability behavior of B4C substrate as well as B4C/crystalline rice husk ash and B4C/amorphous rice husk ash substrates with two aluminum alloys were studied. The electrical resistivity, thermal expansion coefficients, and thermal diffusivity of bilayer Al/B4C/rice husk ash composite fabricated by one-step pressureless infiltration were measured and the obtained data were systemically analyzed using the Taguchi method and analysis of variance. Boron carbide substrates after addition of amorphous or crystalline rice husk ash display good wettability with molten aluminum alloys. The results show that, electrical resistivity of Al/B4C/rice husk ash composites is mainly influenced by initial preform porosity, while the coefficient of thermal expansion of composites is determined by the chemical composition of infiltrated alloys. The measured values for coefficient of thermal expansion (10.5 × 10−6/℃) and electrical resistivity (0.60 × 10−5 Ω.m) of Al/B4C/rice husk ash composites, fabricated according to analysis of variance's optimal conditions are in good agreement with those of the projected values (11.02 × 10−6/℃ and 0.65 × 10−5 Ω.m, respectively). The difference between the corresponding values obtained from verification tests and projected values, for electrical resistivity and coefficient of thermal expansion are less than 5%. Finally, as a material selection approach, the strengths and weaknesses of the composites have been graphed in the form of radar diagrams.

Thermally Induced Synchronous Instability of a Radial Inflow Overhung Turbine: Part I

1997 ◽  
Author(s):  
H. B. Faulkner ◽  
W. F. Strong ◽  
R. G. Kirk
Keyword(s):  
Thermal Expansion ◽  
Operating Speed ◽  
Lateral Motion ◽  
Turbine Wheel ◽  
Thermally Induced ◽  
Lateral Dynamics ◽  
Morton Effect ◽  
Speed Range ◽  
Differential Thermal Expansion ◽  
Rotor Dynamic

Abstract This paper is in two parts, and concerns the lateral dynamics of a large turbocharger rotor with overhung wheels. Initial rotor dynamic analysis indicated no excessive motion in the operating speed range. However, testing showed excessive motion, which was initially traced to the radial-inflow turbine wheel becoming loose on the shaft, due to transient differential thermal expansion in the wheel on startup. The attachment of the wheel was modified to eliminate this problem. The discussion up to this point is in Part I of the paper, and the remainder is in Part II. The wheel attachment modification extended the range of satisfactory operation upward considerably, but excessive lateral motion was again encountered near the upper end of the operating speed range. This behavior was traced to thermal bowing of the shaft at the turbine end, known as the Morton Effect. The turbine end bearing was modified to eliminate this problem, and satisfactory operation was then achieved throughout the operating speed range.

Properties of Graphite Interconnect Circuit Boards with Anisotropic Thermal Expansion

1990 ◽  
Vol 216 ◽  
Author(s):  
J. Malamas ◽  
R.P. Bambha ◽  
J.B. Ramsey ◽  
W.C. Garrett ◽  
E.G. Kelso ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Focal Plane ◽  
Thermal Stresses ◽  
Focal Plane Arrays ◽  
Circuit Board ◽  
Circuit Boards ◽  
Anisotropic Thermal Expansion ◽  
Indium Bump

ABSTRACTWe report the investigation of an interconnect circuit board (ICB) with anisotropic thermal expansion for use with bump bonded, indirect hybrid, scanning focal plane arrays. This ICB is designed to reduce significantly the thermal stresses on the indium bump bonds during thermal cycling. Highly oriented pyrolitic graphite (HOPG) was chosen because its anisotropic thermal expansion meets the criteria for forming an indirect hybrid ICB using silicon processor circuits and mecury cadmium telluride detectors. Properties of HOPG influencing its performance as an ICB have been investigated including thermal expansion, electrical conductivity, durability, and adherence of electrically insulating thin films.

Bi-Material Re-Entrant Triangle Cellular Structures Incorporating Tailorable Thermal Expansion and Tunable Poisson's Ratio1

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Xiaobing He ◽  
Jingjun Yu ◽  
Yan Xie
Keyword(s):  
Thermal Expansion ◽  
Cellular Structure ◽  
Material Selection ◽  
Coefficient Of Thermal Expansion ◽  
Planar Lattice ◽  
Lattice Cell ◽  
Thermoelasticity Equation ◽  
Triangle Lattice ◽  
Temperature Load ◽  
The Relationship

Abstract Based on the bi-material triangle lattice cell, a new cellular structure, bi-material re-entrant triangle (BRT) cellular structure, is devised to incorporate tailorable coefficient of thermal expansion (CTE) and tunable Poisson's ratio (PR) properties by replacing the straight base of a triangle with two hypotenuse members. A general thermoelasticity equation to systematically build the relationship among the external force, the temperature load, and the deformation for planar lattice structures with bounded joints is derived and then embedded into a theoretical model for the devised BRT structure. Using assembled thermoelasticity equation, effective PR, Young's modulus, as well as CTE are computed. In order to guide designers to construct initial concepts, the design domain for coupling negative CTE and negative PR properties is plotted. The material-property-combination region that can be achieved by this cellular structure is determined within an Ashby material selection chart of CTE versus PR. Nine available combinations of CTE and PR properties are extracted and demonstrated with abaqus simulation.

FUZZY BASED DESIGN OPTIMIZATION TO REDUCE THE CROSSTALK IN MICROSTRIP LINES

2004 ◽  
Vol 13 (01) ◽  
pp. 121-136 ◽  
Author(s):  
T. AHMAD ◽  
M. A. HOSSAIN ◽  
A. K. RAY ◽  
Z. GHASSEMLOOY
Keyword(s):  
Fuzzy Logic ◽  
Design Optimization ◽  
High Speed ◽  
Printed Circuit Board ◽  
Optimization Methods ◽  
Circuit Board ◽  
Electrical Parameters ◽  
Design And Optimization ◽  
Printed Circuit ◽  
Microstrip Lines

This paper presents an investigation of the design optimization in microstrip lines to reduce the crosstalk level using Fuzzy Logic. In microstrip lines length and spacing, termination conditions of interconnection and output impedance of gates are the major components that cause crosstalk. In order to design high speed printed circuit board (PCB) with optimum interconnection configuration, it is essential to reduce the crosstalk to its minimum tolerance level. A design methodology is proposed to correlate electrical parameters and physical configuration of lines to the crosstalk phenomena. This design is subsequently optimized using Fuzzy Logic to reduce the level of crosstalk. A set of experiments is carried out to demonstrate the capabilities of the design and optimization methods. The effect of the geometrical configuration of the lines on crosstalk, particularly the spacing, is highlighted.

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