An investigation on story failure modes of frame structures

2007 ◽  
pp. 229-236 ◽  
Keyword(s):  
Failure Modes ◽  
Frame Structures

Upgrading seismic performance of underground frame structures based on potential failure modes

2022 ◽  
Vol 153 ◽  
pp. 107116
Author(s):  
Chunyu Wu ◽  
Dechun Lu ◽  
M. Hesham El Naggar ◽  
Chao Ma ◽  
Qiang Li ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Failure Modes ◽  
Frame Structures ◽  
Potential Failure

Comparative Study on the Effects of Infill Walls on Reinforced Concrete Frame Structures

2015 ◽  
Vol 730 ◽  
pp. 81-84
Author(s):  
Huan Jin
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Shear Failure ◽  
Frame Structure ◽  
Frame Structures ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Infill Walls ◽  
Finite Element Program ◽  
Static Test

Based on the quasi-static test of single-layer, two-bay RC frame model, using DIANA finite element program, a finite element Macro-model of masonry-infilled frame structure was established, and nonlinear finite element analysis of frame structures filled with different masonry materials was conducted. As a result of the existence of infill walls, the failure modes of frame structure have been changed, and which is easy to cause shear failure at the top of frame columns. If masonry materials of infill walls are different, the effects of infill panels on frame structures will be different. Comparative analysis shows that the influence of clay bricks is the largest, followed by autoclaved bricks’ influence, while aerated concrete blocks’ influence is the smallest. Therefore, to avoid the associated failure mechanism caused by infill walls, lightweight masonry materials are suggested to be used in actual engineering.

scholarly journals Influence of Beam-to-Column Linear Stiffness Ratio on Failure Mechanism of Reinforced Concrete Moment-Resisting Frame Structures

2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
Jizhi Su ◽  
Boquan Liu ◽  
Guohua Xing ◽  
Yudong Ma ◽  
Jiao Huang
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Numerical Models ◽  
Frame Structures ◽  
Material Strength ◽  
Stiffness Ratio ◽  
Limit Values ◽  
Failure Patterns ◽  
Moment Resisting Frame ◽  
Moment Resisting

The design philosophy of a strong-column weak-beam (SCWB), commonly used in seismic design codes for reinforced concrete (RC) moment-resisting frame structures, permits plastic deformation in beams while keeping columns elastic. SCWB frames are designed according to beam-to-column flexural capacity ratio requirements in order to ensure the beam-hinge mechanism during large earthquakes and without considering the influence of the beam-to-column stiffness ratio on the failure modes of global structures. The beam-to-column linear stiffness ratio is a comprehensive indicator of flexural stiffness, story height, and span. This study proposes limit values for different aseismic grades based on a governing equation deduced from the perspective of member ductility. The mathematical expression shows that the structural yielding mechanism strongly depends on parameters such as material strength, section size, reinforcement ratio, and axial compression ratio. The beam-hinge mechanism can be achieved if the actual beam-to-column linear stiffness ratio is smaller than the recommended limit values. Two 1/3-scale models of 3-bay, 3-story RC frames were constructed and tested under low reversed cyclic loading to verify the theoretical analysis and investigate the influence of the beam-to-column linear stiffness ratio on the structural failure patterns. A series of nonlinear dynamic analyses were conducted on the numerical models, both nonconforming and conforming to the beam-to-column linear stiffness ratio limit values. The test results indicated that seismic damage tends to occur at the columns in structures with larger beam-to-column linear stiffness ratios, which inhibits the energy dissipation. The dynamic analysis suggests that considering the beam-to-column linear stiffness ratio during the design of structures leads to a transition from a column-hinge mechanism to a beam-hinge mechanism.

Probabilistic Evaluation of Effects of Column Moment Magnification Factor on Seismic Performance of Reinforced Concrete Frames

2011 ◽  
Vol 243-249 ◽  
pp. 251-257 ◽  
Author(s):  
Ming Ji He ◽  
Chun Yang ◽  
Jian Cai ◽  
Yan Sheng Huang ◽  
Yi Wu
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Frame Structures ◽  
Rc Frame ◽  
Magnification Factor ◽  
Rc Frame Structures

Enhancing column flexural capacity is the key measure in seismic capacity design to achieve strong column-weak beam failure mode and determinate the probabilistic relation between column moment magnification factor (CMMF). In the paper the effects of column moment magnification factor on seismic performance of reinforced concrete (RC) frames are evaluated to limit the occurrence probability of column-hinging failure modes within an acceptable tolerance. Monte Carlo simulation methodology is used to calculate the probability of drift demand exceeding drift capacity of two typical frame structures with consideration of major uncertainties. And fragility curves are constructed to obtain the relationship between CMMF and probability of structural damages and assess the seismic vulnerability of RC frame structures. Results show that the seismic performance of RC frame structures can be significantly enhanced by improving CMMF. The CMMF is required to be equal to or greater than 2.0 to achieve acceptable probability of exceedance of column-hinging failure mode.

Automatic generation of stochastically dominant failure modes of frame structures

1984 ◽  
Vol 2 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Y. Murotsu ◽  
H. Okada ◽  
K. Taguchi ◽  
M. Grimmelt ◽  
M. Yonezawa
Keyword(s):  
Failure Modes ◽  
Automatic Generation ◽  
Frame Structures

Basic and Optimum Column Over-Design Factor Avoiding Story Mechanism for Frame Structures

2007 ◽  
Vol 340-341 ◽  
pp. 1405-1410
Author(s):  
Yan Gang Zhao ◽  
Wu Chuan Pu ◽  
Hong Nan Li ◽  
Tetsuro Ono
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Frame Structure ◽  
Frame Structures ◽  
Plastic Hinges ◽  
Design Factor ◽  
Plastic Materials ◽  
Elastic Plastic Materials ◽  
Design Factors ◽  
Specific Tolerance

Ductile frame structures are generally designed with column over-design factors (COF) to assure plastic hinges occurring in all beams and avoid unpreferable failure modes. In order to avoid story mechanisms of frame structure constructed with elastic-plastic materials, target COF has been investigated where the relative occurrence probability of most likely story mechanism is limited within a specific tolerance. In the present paper, the concept of basic and optimum column over-design factor for avoiding story mechanism are proposed and the value of them for multi-span multi-story ductile frames are presented based on a comprehensive investigation on the occurrence order of story mechanisms. The basic COF is defined as the critical value that the preferable failure mode and unpreferable failure mode are with the same failure probability, and it is the low limit assuring the entire beam-hinging pattern prior to story mechanisms. For a structure designed with a COF less than basic COF, the plastic hinges are easier to occur in partial stories to form story mechanism. The optimum COF is the most effective and economy COF to enhance the safety of structure, and it is resulted from the shift of priority of plastic hinges in different stories. The relationships between the basic and optimum COF with calculation parameters are also analyzed in this paper.

Failure Mode Analysis for Column over Designed Ductile Frames

2007 ◽  
Vol 340-341 ◽  
pp. 1393-1398
Author(s):  
Yan Gang Zhao ◽  
Yue Feng Geng ◽  
Kazuhiro Yoshihara
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Plastic Hinge ◽  
Mode Analysis ◽  
Frame Structures ◽  
Identification Procedure ◽  
Design Factor ◽  
Collapse Mode ◽  
Failure Mode Analysis ◽  
External Loads

In ultimate asseismic design of ductile frame structures, plastic deformation and plastic hinge are generally permitted, and some preferred failure modes are often selected. It is an important problem that whether the designed structure collapses according to the designed failure mode, because of the large uncertainties included in external loads and member strength. In this paper, an identification procedure of failure modes for frame structures is developed, and the likely collapse modes of frame structures under uncertain load and member strength are investigated under assumption of normal distributed and non-normal distributed external loads and member strength. It is found that the occurrence order of likely collapse mode is much influenced by the distribution of the random variables. The occurrence order of collapse modes for column over designed structures are investigated and it is found that the increase of column over-design factor can effectively avoid the story collapse mode in probabilistic means.

scholarly journals On Factors behind the Reasonable Failure Mode of Concrete-Filled Circular Steel Tubular Composite Frame

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yang-bing Liu ◽  
Ping-ping Cui ◽  
Fang Chen
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Failure Process ◽  
Pushover Analysis ◽  
Steel Structures ◽  
Element Model ◽  
Basic Structure ◽  
Frame Structures ◽  
Steel Beam ◽  
Model Method

As the most basic structure, the concrete-filled steel tubular (CFST) frame has been widely used in various structures and systems. Compared with conventional reinforced concrete structures and steel structures, CFST structures in strong earthquake showcase more complicated strength and deformation behavior because there are many factors underlying the failure mode. Furthermore, according to the specifications at home and abroad, the corresponding design method to achieve reasonable failure modes for CFST structures has not been clarified. Based on a destructive test on steel beam-CFST plane frames under constant axial load and lateral load, the fiber mode method and solid element model method are adopted to simulate the failure process of the test frames. Based on finite element model simulations and tests, the fiber model method is proposed to carry out the pushover analysis on the CFST frame structures. The factors behind the reasonable failure mode of steel beam-concrete-filled circular steel tubular (CFCST) frame structures are analyzed. Furthermore, the law and influencing factors behind the ratio of flexural capacity of column to beam, the ratio of line stiffness of beam to column, and the ratio of axial compression on the deformation, bearing capacity, and failure modes of the structure are discussed. Some suggestions on the design of reasonable failure mode of steel beam-concrete-filled circular steel tubular (CFCST) frame structures are proposed.

Scanning Electron Microscopy in Hybrid Microelectronics

1976 ◽  
Vol 34 ◽  
pp. 456-457
Author(s):  
S. Khadpe ◽  
R. Faryniak
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Integrated Circuit ◽  
Failure Modes ◽  
Three Dimensional ◽  
Circuit Components ◽  
Hybrid Microcircuit ◽  
Electrical Connections ◽  
Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

Sign in / Sign up

Export Citation Format

Share Document