Bending and Twisting of 60Sn40Pb Solder Interconnects With Creep

1994 ◽  
Vol 116 (2) ◽  
pp. 154-157
Author(s):  
John H. Lau
Keyword(s):  
Creep Deformation ◽  
Material Properties ◽  
Bending Moment ◽  
Engineering Practice ◽  
Solder Material ◽  
Solder Interconnects ◽  
Exact Analysis ◽  
Twist Rate ◽  
Thin Walled ◽  
Interaction Curves

An exact analysis is presented for the creep deformation of a thin-walled circular solder cylinder under the actions of bending and twisting moments. Dimensionless interaction curves and charts which relate the variables, interconnect geometry, solder material properties, bending moment, twisting moment, curvature rate, and twist rate are also provided for engineering practice convenience.

Creep of Thin-Walled Circular Cylinder Under Axial Force, Bending, and Twisting Moments

1984 ◽  
Vol 106 (1) ◽  
pp. 79-83 ◽  
Author(s):  
J. H. Lau ◽  
S. S. Jung ◽  
T. T. Lau
Keyword(s):  
Circular Cylinder ◽  
Strain Rate ◽  
Axial Force ◽  
Effective Strain ◽  
Bending Moment ◽  
Constitutive Relationship ◽  
Engineering Practice ◽  
Shear Strain Rate ◽  
Thin Walled ◽  
Interaction Curves

An exact analysis is presented for the creep deformation of a thin-walled circular cylinder subjected to the simultaneous actions of axial force, bending, and twisting moments. Dimensionless interaction curves and charts which relate the variables, axial force, location of neutral-axis, bending moment, maximum effective strain rate, twisting moment, and shear strain rate are also provided for engineering practice convenience. The constitutive relationship of the cylinder is described by Prandtl-Nadai creep law.

Bending and Twisting of Pipes With Strain Hardening

1984 ◽  
Vol 106 (2) ◽  
pp. 188-195 ◽  
Author(s):  
J. H. Lau ◽  
T. T. Lau
Keyword(s):  
Effective Strain ◽  
Closed Form Solution ◽  
Bending Moment ◽  
Small Deformation ◽  
Form Solution ◽  
Simultaneous Action ◽  
Deformation Analysis ◽  
Engineering Practice ◽  
Strain Diagram ◽  
Interaction Curves

A closed-form solution is presented for the small deformation analysis of a straight thin-walled circular cylinder subjected to the simultaneous action of bending and twisting moments. Dimensionless interaction curves and charts which relate the variables, bending moment, curvature, maximum effective strain, twisting moment, and shear strain are also provided for engineering practice convenience. The average stress-strain diagram of the cylinder is described by two straight lines. The result presented herein is not only a good approximation of a wide class of piping materials, but also provides a standard tool for estimating the accuracy of different direct schemes such as numerical integration, finite-difference, and finite-element methods.

Deformation of Curved Bars With Creep

1985 ◽  
Vol 107 (1) ◽  
pp. 225-230 ◽  
Author(s):  
J. H. Lau ◽  
C. K. Hu
Keyword(s):  
Axial Force ◽  
Maximum Stress ◽  
Bending Moment ◽  
Neutral Axis ◽  
Constitutive Relationship ◽  
Engineering Practice ◽  
Stress And Strain ◽  
Interaction Curves ◽  
Stress And Strain Rate ◽  
Relationship Of

An exact analysis is presented for the creep deformation of a curved bar subjected to the simultaneous actions of bending moment and axial force. Dimensionless interaction curves and charts, which relate the variables, axial force, location of neutral axis, maximum stress and strain rate, bending moment, and change in curvature rate, are also provided for engineering practice convenience. The constitutive relationship of the curved bar is described by the Prandtl-Nadai Creep Law.

scholarly journals Factors Affecting the Compression and Energy Absorption Properties of Small-Sized Thin-Walled Metal Tubes

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoqin Hao ◽  
Jia Yu ◽  
Weidong He ◽  
Yi Jiang
Keyword(s):  
Energy Absorption ◽  
Simulation Models ◽  
Simulation Method ◽  
Engineering Practice ◽  
Small Ring ◽  
Metal Tube ◽  
Absorption Properties ◽  
Factors Affecting ◽  
Thin Walled ◽  
Hollow Metal

To solve the problem of the effective cushioning of fast-moving mechanical components in small ring-shaped spaces, the factors affecting the compression and energy absorption properties of small-sized hollow metal tubes were studied. Simulation models were constructed to analyse the influences of tube diameter, wall thickness, relative position, and number of stacked components on the compression and energy absorption properties. The correctness of the simulation method and its output were verified by experiments, which proved the effectiveness of compression and energy absorption properties of small-sized thin-walled metal tubes. The research provides support for the application of metal tube buffers in armament launch technology and engineering practice.

Geometrical Stiffness of Thin-Walled I-Beam Element Based on Rigid-Beam Assemblage Concept

2012 ◽  
Vol 28 (1) ◽  
pp. 97-106 ◽  
Author(s):  
J. D. Yau ◽  
S.-R. Kuo
Keyword(s):  
Stiffness Matrix ◽  
Virtual Work ◽  
Bending Moment ◽  
Beam Element ◽  
Narrow Beam ◽  
Cross Sectional ◽  
Geometric Stiffness ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Thin Walled

ABSTRACTUsing conventional virtual work method to derive geometric stiffness of a thin-walled beam element, researchers usually have to deal with nonlinear strains with high order terms and the induced moments caused by cross sectional stress results under rotations. To simplify the laborious procedure, this study decomposes an I-beam element into three narrow beam components in conjunction with geometrical hypothesis of rigid cross section. Then let us adopt Yanget al.'s simplified geometric stiffness matrix [kg]12×12of a rigid beam element as the basis of geometric stiffness of a narrow beam element. Finally, we can use rigid beam assemblage and stiffness transformation procedure to derivate the geometric stiffness matrix [kg]14×14of an I-beam element, in which two nodal warping deformations are included. From the derived [kg]14×14matrix, it can take into account the nature of various rotational moments, such as semi-tangential (ST) property for St. Venant torque and quasi-tangential (QT) property for both bending moment and warping torque. The applicability of the proposed [kg]14×14matrix to buckling problem and geometric nonlinear analysis of loaded I-shaped beam structures will be verified and compared with the results presented in existing literatures. Moreover, the post-buckling behavior of a centrally-load web-tapered I-beam with warping restraints will be investigated as well.

scholarly journals Flexural-Torsional Vibration of Thin-Walled Beams Subjected to Combined Initial Axial Load and End Bending Moment: Application to the Design of Saw Tooth Blades

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Van Binh Phung ◽  
Anh Tuan Nguyen ◽  
Hoang Minh Dang ◽  
Thanh-Phong Dao ◽  
V. N. Duc
Keyword(s):  
Boundary Conditions ◽  
Axial Load ◽  
Stability Boundary ◽  
Bending Moment ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Rayleigh Method ◽  
Thin Walled ◽  
The Stability ◽  
Fixed End

The present paper analyzes the vibration issue of thin-walled beams under combined initial axial load and end moment in two cases with different boundary conditions, specifically the simply supported-end and the laterally fixed-end boundary conditions. The analytical expressions for the first natural frequencies of thin-walled beams were derived by two methods that are a method based on the existence of the roots theorem of differential equation systems and the Rayleigh method. In particular, the stability boundary of a beam can be determined directly from its first natural frequency expression. The analytical results are in good agreement with those from the finite element analysis software ANSYS Mechanical APDL. The research results obtained here are useful for those creating tooth blade designs of innovative frame saw machines.

Computational Modeling and Energy Absorption Behavior of Thin-Walled Tubes with the Kresling Origami Pattern

2021 ◽  
Vol 62 (2) ◽  
pp. 71-81
Author(s):  
Jiaqiang Li ◽  
Yao Chen ◽  
Xiaodong Feng ◽  
Jian Feng ◽  
Pooya Sareh
Keyword(s):  
Energy Absorption ◽  
Material Properties ◽  
Rotation Angle ◽  
Programming Model ◽  
Mixed Integer ◽  
Element Analysis ◽  
Cross Sectional ◽  
Thin Walled Tube ◽  
Absorption Performance ◽  
Thin Walled

Origami structures have been widely used in various engineering fields due to their desirable properties such as geometric transformability and high specific energy absorption. Based on the Kresling origami pattern, this study proposes a type of thin-walled origami tube the structural configuration of which is found by a mixed-integer linear programming model. Using finite element analysis, a reasonable configuration of a thin-walled tube with the Kresling pattern is firstly analyzed. Then, the influences of different material properties, the rotation angle of the upper and lower sections of the tube unit, and cross-sectional shapes on the energy absorption behavior of the thin-walled tubes under axial compression are evaluated. The results show that the symmetric thin-walled tube with the Kresling pattern is a reasonable choice for energy absorption purposes. Compared with thin-walled prismatic tubes, the thin-walled tube with the Kresling pattern substantially reduces the initial peak force and the average crushing force, without significantly reducing its energy absorption capacity; moreover, it enters the plastic energy dissipation stage ahead of time, giving it a superior energy absorption performance. Besides, the material properties, rotation angle, and cross-sectional shape have considerable influences on its energy absorption performance. The results provide a basis for the application of the Kresling origami pattern in the design of thin-walled energy-absorbingstructures.

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