This paper is to investigate the effects of Soil-Structure Interaction (SSI) on the dynamic response of a soil-structure system. An ideal model with a simple structure supported on elastic half space is utilized to derive the factor FSSI that can completely represent the effects of SSI. This factor is able to characterize both the change of predominant frequency and damping ratio of the system when compared to the conventional rigid-base type structural analysis. Based on that, an Equivalent Fixed-Base (EFB) model, which takes the effects of SSI into account, can be constructed. The Hualien field test results are then used to verify the applicability of the proposed EFB model.

In this paper, a theory of Endochronic cyclic viscoplasticity of eutectic Tin/Lead (60Sn/40Pb) solder alloy under cyclically thermomechanical strain histories had been established. Under the conditions of isotropic and inelastically incompressible small deformation, the constitutive equation of deviatoric behavior was expressed as:

here and the strain rate dependent intrinsic time scale and . Employing the experimental cyclic shear stress-strain curves of various testing temperature and frequency, all temp. dependent material parameters and ; and the temp.-freq. dependent material function were determined for temp. between 213K and 423K and freq. between 0.3Hz and 0.01Hz. Predicative capability of the theory were then challenged by a set of experiments with complicate strain history such as (i) Fast in tension/Slow in compression constant strain amplitude cyclic tests (ii) Slow-Fast-Slow constant amplitude cyclic tests. Through the excellent computational results, the present theory demonstrated that it can, not only play a vital role in the area of electronic solder mechanics, but also meet the needs of reliability analysis and life assessment in the electronic/photoelectronic packagings.

Low-frequency variations in wake flow are complex and many aspects of its behavior remain poorly understood. A mode decomposition method developed by Huang et al is utilized herein because it can decompose any complicated data set into a finite number of intrinsic modes without distorting their original characteristics. The results of decomposition analysis of the measured base pressure signals reveal that a finite number of various kinds of flow structure modes, with their own characteristic time scales, coexist with the residue that exhibits most of the low-frequency variations in flow at Re = 11760 and 31600, respectively. As the Reynolds number increases, the decomposition method yields more components. Results also show exactly the vortex shedding structure in an intrinsic mode and the low-frequency variations that appear in the residue during vortex shedding process.

In this paper, a simpler formulation for the nonlinear motion analysis of reticulated space truss structures is developed by applying a new concept of computational mechanics, named the vector form intrinsic finite element (VFIFE or V-5) method. The V-5 method models the analyzed domain to be composed by finite particles and the Newton's second law is applied to describe each particle's motion. By tracing the motions of all the mass particles in the space, it can simulate the large geometrical and material nonlinear changes during the motion of structure without using geometrical stiffness matrix and iterations. The analysis procedure is vastly simple, accurate, and versatile. The formulation of VFIFE type space truss element includes a new description of the kinematics that can handle large rotation and large deformation, and includes a set of deformation coordinates for each time increment used to describe the shape functions and internal nodal forces. A convected material frame and an explicit time integration scheme for the solution procedures are also adopted. Numerical examples are presented to demonstrate capabilities and accuracy of the V-5 method on the nonlinear dynamic stability analysis of space truss structures.

In this study, physical and numerical models were used to analyze pipe-soil interaction during pipejacking work. After calibrating with the physical modeling results, the finite element software ABAQUS [1] was used to study the pipejacking related behavior, such as surface subsidence, failure mechanism, pipe-soil interaction, etc. The results show that the driving force in the tunnelling face is very important and critical for pipejacking. Surface subsidence is mainly due to the lack of driving force, however, excessive driving force could cause the unfavorable surface heaving problem. It also suggests that the depth of the pipe is critical to determine a proper driving force to stabilize the tunnelling face.

The effect of Coriolis force on the rivulet (fingering) instability, the onset of rivulet phenomena during spin coating, is investigated by flow visualization experiments incorporating with dimensional analysis. This study demonstrates that the Coriolis force will affect significantly the critical radius of rivulet instability and the deflection angle of instability rivulet. For the cases of low Bond number, the effect of Coriolis force is a stabilizing factor, and the dimensionless critical radius increases slightly with increasing rotational Reynolds number Reω. In the case of high Bond number, the effect of Coriolis force becomes a destabilizing factor while Reω < 1, and a characteristic length is found by balancing the viscous force with the surface tension. For Reω > 1, the radial Corilois force, which is always pointing inward, plays a stabilizing role with magnitude Reω2.

An approach to establish a master curve for effective creep compliances of polymeric off-axis composites with various fiber orientations was presented. Carbon/epoxy composite IM7/977–3 was used to fabricate four types of off-axis specimens and then subjected to momentary creep tests after a period of initial aging. Creep compliance and elastic compliance were separated from the total compliance. Using one-parameter creep potential theory, creep compliances were transformed to effective creep compliances. After choosing a proper value for the one-parameter, all effective creep compliances with various off-axis fiber orientations were superposed into a master curve. This master curve enables us to obtain creep compliance with any off-axis fiber orientation by testing only one off-axis specimen.

This paper develops the method of fundamental solutions (MFS) to solve eigenfrequencies of plate vibrations of multiply connected domains. The complex-valued MFS combined with the mix potential method are utilized in order to avoid the spurious eigenvalues. The benchmarked problems of annular plates with clamped, simply supported and free boundary conditions are studied analytically as well as numerically. Wherein the results demonstrate that all true eigenvalues are contained and no spurious eigenvalues are included. In the analytical studies, the continuous version of the MFS is utilized to obtain the eigenequation by applying the degenerate kernels and Fourier series. The proposed numerical method is free from singularities, meshes, and numerical integrations and thus can be easily utilized to solve plate vibrations free from spurious eigenvalues in multiply connected domains.

The purpose of the present study is to investigate laminar fully developed flow in a horizontal rectangular channel with a cylinder solutal source adjacent to planar boundary. The boundaries in this experiment include four cases:

(A) Cylinder is cathode and top plate is anode;

(B) Cylinder is anode and top plate is cathode;

(C) Cylinder is cathode and bottom plate is anode;

(D) Cylinder is anode and bottom plate is cathode.

The influences of the mass transfer rate and the boundary types between the sources have also been investigated. An experimental investigation of mixed convection mass transfer between a cylinder and a plate mass source with an electrochemical system is carried in a horizontal rectangular channel. The working fluid here is CuSO4 + H2SO4 + H2O. The shadowgraph technique is used to visualize the flow and to determine the nature and effect of solutal driven secondary flows in a horizontal channel. The ranges of the parameters in the work are Pr = 7, Ar = 1, Sc = 1700 ∼ 2400, Re = 50 ∼ 200 (Red= 12.5 ∼50), Grm = 9.45 × 105, d/H = 0.25, h/d=0, 3.

This work studies the natural convection heat and mass transfer near a horizontal cylinder of elliptic cross section with constant wall temperature and concentration in a fluid-saturated porous medium. A coordinate transformation is used to obtain the nonsimilar governing boundary layer equations. The transformed governing equations are then solved by the cubic spline collocation method. Results for the local Nusselt and Sherwood numbers are presented as functions of the Lewis number, the buoyancy ratio, and the aspect ratio when the major axis of the elliptical cylinder is vertical (slender orientation) and horizontal (blunt orientation). The heat and mass transfer rates of the elliptical cylinder with slender orientation are higher than those with blunt orientation.