Papers by Keyword: Failure Pattern

Abstract: Experience gained in design, erection and operation of span reinforced concrete structures has proved that practically all of them are subject to complex stress-strain state. At that, the researchers pay considerable greater attention to calculation of strength, deformation analysis and determination of crack resistance in normal cross-sections than to calculation of their support zones, including oblique sections, which results are generally taken into account for determining the section dimensions and the quantity of the cross reinforcement.

Abstract: The partially infilled frames are considered vulnerable in terms of captive column effect for the events of earthquakes. Many reinforced concrete buildings have been affected due to captive column effects. Experimental study has been done to verify the captive column effect and its failure modes for partially infilled frames and the results have been compared with the ones obtained for a bare frame subjected to lateral loading. The results of experimental study have also been compared with some analytical results and the verification of equivalent strut width proposed by one of the authors has been done. From the experimental point of view, it is understandable that due to lateral loading to partially infilled frames, the damage pattern is diagonal and the failure of column occurs at the column-wall joint at the upper side of the wall. It is also seen that for fifty percent partially infilled frames, the stiffness of bare frame is enhanced slightly, however, the failure in the column during lateral loading indicates that the columns are subjected to high shear due to the presence of partial infill.

Abstract: This paper proposed an empirical relative variation coefficient to improve performance of cellular automata model which was put forward by Zhou^[1] to predict failure patterns of masonry wall panels under lateral load. The improved empirical cellular automata model could take discreteness of failure patterns into account. Then, parameter analysis of the empirical variation coefficient was conducted to find out its reasonable value interval. Consequently, a serial failure patterns could be predicted on the basis of each experimental record. A comparison between predicted failure patterns and experimental results has been made, which proved the empirical cellular model with relative variation coefficient was not only one-to-multiple, but also valid.

Abstract: Numerical simulations the different rock sample in the uniaxial compression have been conducted using Rock Failure Process Analysis program (RFPA^2D) to evaluate the effects of joint trace lengths on the overall mechanical behaviour of jointed rock masses in this paper. Numerically simulated stress-strain curve, peak stress, peak strain and failure patterns were compared with the corresponding experimental results. We found that for a series of partially-spanning joint geometries with the same joint orientation, the projected area will be proportional to the square of the trace length. Thus, the relationship between compressive strength and partially-spanning joint geometry for the tests carried out to explore the influence of joint trace length may be expressed as a linear correlation between compressive strength and projected area.Numerical simulations agree well with experimental results.

Abstract: In this paper,the mechanical properties of rock experiencing the variation of joint tip distance from sample end under uniaxial compression condition were simulated.Numerical simulation for the different rock sample in the uniaxial compression have been conducted to evaluate the effects of joint tip distance from sample end on the overall mechanical behaviour of jointed rock masses. It was done using the Rock Failure Process Analysis program RFPA^2D. Numerically simulated stress-strain curve, peak stress, peak strain and failure patterns were compared with the corresponding physical tests. We found that specimen joint tip distance from sample end corresponding value (distance from the crack tip to the compression surface) linear relationship with the compressive strength values .Numerical simulations agree well with physical results, it is shown that RFPA^2D is suitable for the analysis of joint tip distance from sample end effect on rock fracture.

Abstract: The mechanical properties of rock experiencing the variation of joint orientation under uniaxial compression condition were simulated in this paper. Numerical simulations on rock sample in uniaxial compression have been conducted to evaluate the effects of joint orientation on the overall mechanical behaviour of jointed rock masses. It was done using the Rock Failure Process Analysis program RFPA^2D. Numerically simulated stress-strain curve, peak stress, peak strain and failure patterns were compared with the corresponding physical tests. Numerical simulations agree well with physical results, it is shown that RFPA^2D is suitable for the analysis of joint orientation effect on rock fracture.

Abstract: This study describes the principles of synthesis and technological features of composition ceramics formation on the basis of silicon carbide and aluminum nitride by hot-pressing. The structural properties and composition of the ceramics were investigated by scanning electron microscope and the formation of the solid solution is confirmed. The elements distribution on the surface of failure pattern is shown. The results of the study are useful for optimization of manufacturing process of structural and functional high-density ceramics.

Abstract: This paper presents an approach to investigate the mechanical properties and failure patterns of shape memory alloy (SMA) by experimental methods. Tests were carried out under the conditions of uniaxial tension, cycling loading and impact-tension respectively. The mechanical behaviors of NiTi SMA such as the relationship of stress-stain, super-elasticity, high damping, energy dissipation and tension-shock toughness are discussed in detail. In addition, the destroy patterns of SMA materials are analyzed for varying condition of testing. Whether ductile failure or brittle fracture is decided to do much with the testing styles and strain rate of materials. It is shown that with the large restoring deformation, higher energy dissipation factor and tension-shock toughness, so NiTi SMA structural functional materials are very suitable for vibration control in engineering.

Abstract: In order to study failure mechanism of the transmission tower caused by longitudinal tensions under icing conditions, with the model of # 43 cup-tower in 500kV Warsaw I line accident segment as for example and the software of large general-purpose finite element analysis, respectively, this paper analyzed their failure characteristics under three conditions that is non-uniform ice-coating, asynchronous ice-shedding and excessive icing,obtaining weak locations. The results will provide reference for the designing work of this type towers in transmission line which is auto-ice designing, enhancement, enforcement, transformation and reconstruction.

Abstract: The pullout test of an anchor bolt is very important for the anchorage technology. Adopting enlarged bottom anchor bolts to wind turbine foundations can not only take advantage of the mechanical property of rock mass, but also have good security and economical efficiency. The finite element analysis software ANSYS is used in this paper to numerically analyze a single enlarged bottom anchor bolt under pullout loading, to research the performance and failure pattern of the anchor bolt. The anchor bolt side friction is extracted to understand the stress distribution of the bolt. By the analysis of the bearing capacity of anchor's enlarged head and the change of plastic zone form, the ultimate strength and destruction form of the anchor blot are clearly understood. The results also show that the bearing capacity of the proposed enlarged bottom anchor bolt can obviously increased, resulting in a cone-shape failure pattern of soil.