This study investigates the recrystallization phenomenon of strain hardening during welding process in austenitic stainless steel (SUS316), and a suitable annealing temperature for finite element method (FEM) simulation was proposed. The electron backscatter diffraction (EBSD) analysis results 1-pass with surface machining proved that effect can be introduced owing to welding. Therefore, it necessary introduce into FEM simulate this phenomenon. hardness changes behavior microstructure after...

GNSS-RTK offers numerous advantages and broad prospects in structural dynamic monitoring civil engineering. However, practical applications, accuracy is susceptible to the environments, causing actual fall below its calibrated accuracy. This study investigates spectral characteristics of based on stability tests under different environments related reflection obstruction conditions (i.e., concrete, grass, an obstructed balcony, a water area). The findings indicate that open water, standard...

Abstract The effects of strain hardening and recovery/recrystallization on the hardness heat-affected zone (HAZ) in multilayer welded austenitic stainless steel SUS316 were investigated this study. results revealed that due to welding softening dominant factors affecting change HAZ during process. Furthermore, relationship between dislocation density quantitatively using positron annihilation lifetime spectroscopy. Based these results, a new prediction method based was proposed. values after...

Porosity in fibre laser welds of two thixomolded heat resistant magnesium alloys AE42 and AS41 was investigated detail, porosity formation mechanism discussed terms gas compositions porosity. It is found that the area percentage decreases with increasing welding speed, can be correlated to width weld metal. Microstructure observation composition analysis show mainly attributed micropores pre-existing base metals during melting by welding, which are formed due air entrapment thixomolding...

A numerical model based on cellular automaton algorithm is developed to simulate dendrite growth at the edge of weld molten pool and solute diffusion during grain growing process in solidification analysed too. By means two-dimensional square cells von Neumann neighbourhood, morphologies columnar dendritic grains with different cooling rates numbers seeds are simulated. The secondary arms, tertiary arms their competitive also presented. results illustrate that final primary spacing depends...

A new thermal cycle tempering parameter (TCTP) to characterize the effect during multi-pass cycles has been proposed by extending Larson-Miller (LMP) non-isothermal heat treatment. Experimental results revealed that hardness in synthetic HAZ of low-alloy steel subjected a good linear relationship with TCTP. The prediction system was constructed using neural network taking into consideration welding, estimated Based on numerically obtained FEM and experimentally database, distribution welded...

This study investigated the effects of coupled thermo-hydro- mechanical dynamics on an isotropic, uniform, fully saturated, and poroelastic half-space subgrade whose surface is subjected to either force or thermal load. In this paper, our formulation deduced in context two theories generalized thermoelasticity: Lord-Shulman theory Green-Lindsay theory. We then deduce general relationships among non-dimensional vertical displacement, excess pore water pressure, stress, temperature...

Rod fastened rotor is widely used as one kind of structures gas turbine rotors. Due to its discontinuity, the stiffness combined different from integral rotor. In order obtain dynamic rod rotor, contact needs be calculated. There are two main methods calculate contact. One focus on microscopic spots in based fact that maching surface full asperities. Hertz theory and Greenwood model under both moment preload. The other method finite element assumes surfaces absolutely smooth which...

Fiber-reinforced materials have widespread applications, which prompt the study of effect fiber reinforcement. Research studies indicated that thermal conductivity cannot be considered as a constant, is closely related to temperature change. Based on those studies, we investigate fiber-reinforced generalized thermoelasticity problem under stress, with consideration temperature-dependent variable conductivity. The assessed according L-S theory. A anisotropic half-space selected research...

Under the action of wind, traffic, and other influences, long-span bridges are prone to large deformation, resulting in instability even destruction. To investigate dynamic characteristics a concrete-filled steel tubular arch bridge, we chose global navigation satellite systems-real-time kinematic (GNSS-RTK) monitor its vibration responses under ambient excitation. A novel approach, use complete ensemble empirical mode decomposition with adaptive noise combined wavelet packet (CEEMDAN-WP) is...

A quill-shaft coupling-rotor-bearing system is modeled and reported in this paper. The consists of two rotors connected by a coupling which each rotor supported bearings. stiffness matrix the deduced equation motion obtained using finite element method. Finally, rotordynamics analysis conducted. numerical results show that more frequency veering points occur for compared with those single rotor. In addition, flexural has significant effects on first bending natural quill shaft when length...

Abstract With the increasing number of long span bridges, real-time, accurate and continuous monitoring their safety is important at present. This study investigates combination a global navigation satellite system (GNSS) accelerometer for dynamic semi-static characteristics bridge structures. A field experiment was conducted with integration GNSS accelerometer. Considering noise interference monitoring, performance tests were first in different environments to investigate characteristics....

Tropospheric delay is one main factor affecting the accuracy of precise point positioning (PPP) ambiguity-float and fixed solutions. Investigations mainly focused on evaluating contributions tropospheric corrections to reliability PPP The generally contained zenith (ZTD) horizontal gradients estimated from relative or PPP. However, delays can be partly absorbed by carrier phase residuals if stochastic model not well-defined. Therefore, along with ZTD gradients, backward filter are considered...