Open Access
ARTICLE
Shang Yang1, Sun Xiangyi, Yang Xia, Wang Xi, Yu Qifeng
Structural Longevity, Vol.5, No.1, pp. 1-15, 2011, DOI:10.3970/sl.2011.005.001
Abstract A new method of camera calibration is proposed for high-precise
videometrics in large field. The camera to be calibrated and the control points used
in the new method are both close to the ground. In the condition that the control
points and the optical center of the camera are approximately coplanar, the principle
point position, focal length, lens distortion coefficients and the camera’s position
and attitude parameters are calibrated precisely by the method. Two calibration
images are taken by the camera to be calibrated in measurement state and vertical
rotation state respectively. If the vertical tangent lens distortion can be… More >
Open Access
ARTICLE
H. X. Zhu1
Structural Longevity, Vol.5, No.1, pp. 17-24, 2011, DOI:10.3970/sl.2011.005.017
Abstract Simple analytical results for the size-dependent elastic properties of
micro- and nano-sized regular open-celled foams are presented in this paper. The
results indicate that at micrometer scale, strain gradient has a dominant effect and
at nanometer scale, surface elasticity dominates the effect on the honeycomb elastic
properties. In addition, very small micro- or nano- open-celled foams could have a
negative Poisson ratio, the elastic properties of nano-sized open-cell foams can be
controlled to vary over a range up to around 66% by the application of an electric
potential. More >
Open Access
ARTICLE
C.T. Kwan, C.C. Wang1
Structural Longevity, Vol.5, No.1, pp. 25-32, 2011, DOI:10.3970/sl.2011.005.025
Abstract In this paper, a pre-stress die design method for cold backward extrusion with a non simple hollow cylinder die by using response surface method is
proposed. The radius of the interface and the absolute interference in the interface
of a prestress die are chosen as the design variables. Both the two design variables
are set at four levels, and then 16 combinations of design parameters are constituted
totally. A finite element based code is utilized to investigate the elastic deformation
characteristic under different design parameters, and the response surface method
is then employed to synthesize the data sets obtained from… More >
Open Access
ARTICLE
Dein Shaw1, Chih Ren Huang1, Yi Chi Pan1
Structural Longevity, Vol.5, No.1, pp. 33-38, 2011, DOI:10.3970/sl.2011.005.033
Abstract A nonlinear curved spring has a free form shape. In this study, the
curved beam is applied a nonlinear load, the load on the spring is pointed to a certain point of the space. This curved spring can be used in an orthosis. A certain
load-deformation relation of curved spring which used in orthosis can assist the
subject wearing the orthosis to climb the stairs. The analysis of the curved spring
should be non-linear due to the applied load is a constant but its direction is point
to a certain point. The deformation is hard predicted correctly for this spring.… More >
Open Access
ARTICLE
Hongwei Guo1
Structural Longevity, Vol.5, No.1, pp. 39-47, 2011, DOI:10.3970/sl.2011.005.039
Abstract This paper presents a moiré-based technique for measuring the threedimensional shapes of specular surfaces. In it, a Ronchi grating is closely located
before the measured object and illuminated by diffusive light sources. When we
observe the measured object through this grating, moiré fringes are generated by
the superposition of this grating and its virtual image produced by the measured
specular surface. With this scheme, the movements of the grating along the vertical
direction introduce phase shifts in these moiré fringes so that their phases can be recovered by use of a self-calibrating phase-shifting algorithm. From the phases and
phase shifts,… More >
Open Access
ARTICLE
P. Zhao1, G. Shi2
Structural Longevity, Vol.5, No.1, pp. 49-58, 2011, DOI:10.3970/sl.2011.005.049
Abstract The Poisson’s ratios of a single layered graphene sheet and singlewalled carbon nanotubes (SWCNTs) are computed using an improved equivalent
structural mechanics model where the bond angle variations are modeled by the
flexible connections of framed structures. The accuracy of the results given by the
present model is evaluated by comparing the predicted results with the experimental
data and the theoretical and computational results reported in the literature. It is
shown that the Poisson’s ratios given by the present computational model agree
with the experimental data. The present result shows that the Poisson’s ratios of
both graphene and SWCNTs are… More >
Login
Register
Submit a Paper