Abstract: Inelastic analysis procedures may be useful as a first approximation for the seismic
response of a structure. The Capacity Diagram Method procedure, which is based on R--T
(Reduction-ductility-Period) relationships, is investigated to compare with the modified CDM
procedure. The CDM procedure is applied to the example model, which is moment resistant RC
frame. Two seismic hazard categories having exceedance probabilities of 2% in 50 years and 10%
in 50 years earthquake ground motions have been selected for evaluating the performance of the
example model. The performance objective of the example model is represented by the combination
of a structural performance level and an earthquake hazard level.
Abstract: The stress characterization around the hole in a composite plate under tensile stress has
been studied by the analytical method in this paper. The distribution of the stress components has
been presented. With the Hashin Failure Criterion, the failure characterization and different failure
modes by the analytical method and finite element method are then studied. The possibility of the
failure in different modes is compared. It is found that the fiber breakage, matrix failure and
delamination are dominant. The place of the failure is between 70 degree and 90 degree to the
loading direction in this paper. The results from analytical method and finite element method can
agree with each other. And they are all confirmed by the experiment results.
Abstract: The fuel-air mixture explosion incidents in the large-scale metal oil storage tank are frequent
occurrence and rapidly extend because of the tank structure being fractured and damaged by the fuel-air
mixture explosion. In this paper, the simulation experiment and numerical simulation has been carried out for
the fuel-air mixture explosion in the large-scale metal storage tank. The shock waves characteristic of the
explosive pressure has been studied and discussed. The fracture and damage effects caused by the shock
waves characteristic to the tank structure has been analyzed and discussed too.
Abstract: Thermal stress, plastic slip deformation and accumulation of dislocations in shallow
trench isolation (STI) type ULSI devices when the temperature drops from 1000 し to room
temperature are analyzed by a crystal plasticity analysis cord. The results show that dislocation
accumulation takes place at the temperature range over 800 し, and the difference of 6 MPa in the
lattice friction stress at 1000 し!causes increase of dislocation density more than 1.6 times.
Dislocations generate and accumulate at the shoulder part of the device area and bottom corners of
the trench. Dislocations are categorized into two groups. In one group, dislocation lines are
mostly straight and parallel to the trench direction, and in the other group, dislocations make half
loop type structure. Possibilities for the suppression of dislocation accumulation through control
of lattice friction stress at high temperature region are discussed.
Abstract: This work is focussed on the numerical prediction of the fracture resistance of a flat fullscale
aluminium alloy 2024 T3 stiffened panel under monotonic traction loading condition. The
numerical simulations are based on the micromechanical Gurson-Tvergaard (GT) model for ductile
damage. The applicability of the GT model to this kind of structural problem has been studied and
assessed by comparing numerical results, obtained by using the WARP 3D finite element code, with
experimental data provided from literature.
Abstract: Fatigue reliability theory has recently verified that the sampling size related effect should
be taken into account by confidence (C). However, most of the historic probabilistic S-N curves are
given to only consider the scattered regularity effect by survival probability (P). Therefore, a
reconstruction method of the historic curves is investigated to consider the sampling size effect. An
effort is made on addressing the true production that the sampling size is less than 20 for material
specimens and 10 for structural component specimens. A Monte Carlo simulation approach is first
established to reconstruct the test S-N data. And then, the P-C-S-N curves are reconstructed with a
general maximum likelihood principle. The practice for 40Cr steel has clearly indicated that, beyond
all doubt, the reconstructed curves has overcome the shortages of the historic data.
Abstract: In recently years, ruby fluorescence spectroscopy has been demonstrated as a powerful
technique for monitoring residual stress evolution in the thermally grown oxide scale in thermal
barrier coatings(TBC) systems. The measured residual stresses, in turn can be used to monitor
evolution of damage in the coatings. Effective use of this technology for real time damage
monitoring require the identification of strength in measured stresses that can be used as indicators
of damage evolution.the present work focuses on studying the evolution of residual stresses in TBC
systems during oxidation. The coating are atmospheric plasma sprayed (APS), the residual stress
were measured at different oxidation time and to identify critical features so as to be used as
indicators of failure in TBCs.
Abstract: Stress intensity factor of crack ahead of notch is important for understanding
the failure of this kind structure. In this paper, a model is proposed to calculate the stress
intensity factor of crack ahead notch configuration under bending load, the modeling
value were verified by the data from literatures and experimental data of this paper, the
trend of the value from model is agreement with that from experiments.
Abstract: There is a macro-crack and micro-crack system in rock, which affects almost all the
mechanical properties of rock, especially for the fracture mechanism. The propagation of
pre-existing cracks in rock samples under load is fundamental to understanding of rock fracture
mechanisms. It is evident that assumption of Griffith theory was not in accord with the fact that
numerous cracks exist in rock. So, it is difficult to explain how the propagation of a micro-crack
developed into macro-failure by conventional theories. In order to investigate the cause and results
of fracture within the rock, the stress concentration around the micro-cracks was analyzed, which
resulted in propagation of wing cracks and connecting adjacent original cracks, eventually leading
to macro-failure. The experiments on gypseous samples with pre-existing parallel cracks (flat
rectangular in shape) under compression were carried out. The fracture mechanism and the stress
equilibrium condition at brittle rock were discussed. Based on the fracture mechanism of brittle
rock, a strength criterion of rock was proposed.
Abstract: An efficient and accurate numerical program with enhanced point collocation meshfree
method is developed to simulate crack propagation under dynamic loading conditions. The enhanced
meshfree method with point collocation formulation and derivative approximation in solids is
presented. This study also presents the crack propagation criterion and computation of propagating
direction, and the total structure of the numerical program named PCMDYC(Point Collocation
Meshfree method for DYnamic Crack propagation). Several examples of crack propagation under
dynamic loads are analyzed to simulate the arbitrary crack propagation under dynamic loads. The
results show that PCMDYC predicts the propagating path of crack under dynamic loading conditions
accurately and robustly.