Experimental Study on the Collapse Strength of Narrow Stiffened Panels

2011 ◽  
Author(s):  
Mingcai Xu ◽  
C. Guedes Soares
Keyword(s):  
Ultimate Strength ◽  
Longitudinal Direction ◽  
Strain Gauges ◽  
Load Carrying Capacity ◽  
Stiffened Panels ◽  
Modes Of Failure ◽  
Collapse Strength ◽  
Tension Tests ◽  
Load Carrying ◽  
Strength Behavior

The results of four tests on narrow stiffened panels under axial compression until collapse and beyond are presented to investigate the ultimate strength of stiffened panels. Tension tests are used to evaluate the material properties of the stiffened panels. The tests are made on panels with two half bays plus one full bay in the longitudinal direction. Initial loading cycles were used to relief the residual stresses of the stiffener panels. The strain gauges are set on the plates and stiffeners to record the distribution of strain. The displacement load relationship is established. The ultimate strength behavior, modes of failure and load-carrying capacity of the stiffened panels are investigated with the experiment.

Experimental Study on the Collapse Strength of Narrow Stiffened Panels

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Ming Cai Xu ◽  
C. Guedes Soares
Keyword(s):  
Carrying Capacity ◽  
Longitudinal Direction ◽  
Strain Gauges ◽  
Load Carrying Capacity ◽  
Stiffened Panels ◽  
Modes Of Failure ◽  
Collapse Strength ◽  
Tension Tests ◽  
Load Carrying ◽  
Collapse Behavior

The results of five tests on narrow stiffened panels under axial compression until collapse and beyond are presented to investigate the collapse behaviors of stiffened panels. Tension tests were used to evaluate the material properties of the stiffened panels. The tests were made on panels with two half bays plus one full bay in the longitudinal direction. Initial loading cycles were used to eliminate the residual stresses of the stiffener panels. The strain gauges were set on the plates and the stiffeners to record the strain histories. The displacement load relationship was established. The collapse behavior, modes of failure and load-carrying capacity of the stiffened panels are investigated with the experiment.

Investigation on the Post-Ultimate Strength Behaviour of Sandwich Plate

2014 ◽  
Author(s):  
Wei Wang ◽  
Weijun Xu ◽  
Xiongliang Yao ◽  
Nana Yang
Keyword(s):  
Ultimate Strength ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Sandwich Plate ◽  
Experimental Results ◽  
Sandwich Plates ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Behavior ◽  
Simulation Results

This paper focuses on the post-ultimate strength behavior of sandwich plates. With widely application of the laminate on the ship and offshore structures, the post-ultimate strength behavior is becoming more important for safety evaluation of structures. Since the post-ultimate strength behavior can reflect the collapse extent of sandwich plate when subjected to extreme loads. A sandwich plate was modeled by FEM, its load-displacement relationship was obtained and its collapse characteristics were analyzed. The load-displacement relationship indicates its post-ultimate strength behavior, which is shown as that the load carrying capacity has a rapidly reduction when the ultimate strength is exceeded, and that the failure modes of the sandwich plate are determined by the parameter of individual layer. The simulation results were validated against experimental results. Conclusions are drawn: the displacement of sandwich plate under axial compression increased slowly before reaching the ultimate strength, once the ultimate strength was exceeded, the loads exerted on the structures sharply decreased with slowly increased displacement until the plate cracked. The simulation results have a good agreement with the experimental results. The mainly failure modes of sandwich plates can be interpreted as delamination between skin & core and core compression fracture, which are typical failure modes in engineering. The stiffness of sandwich structures decreased due to the interlaminar cracking or skin fracture, further the load carrying capacity decreased, which is of significance for guiding the design of sandwich structures.

Ultimate Strength of Damaged Stiffened Panels Subjected to Uniaxial Compressive Loads Accounting for Impact Induced Residual Stress and Deformation

2015 ◽  
Author(s):  
Jie Cai ◽  
Xiaoli Jiang ◽  
Gabriel Lodewijks
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Carrying Capacity ◽  
Stiffened Panel ◽  
Load Carrying Capacity ◽  
Stiffened Panels ◽  
Load Carrying ◽  
Stress And Deformation ◽  
The Impact ◽  
Residual Stress And Deformation

In case of ship accidents, the ship’s hull will inevitably suffer from damages such as holes, cracks, dent etc., which will threaten the structural safety of ship. It is essential to study the ultimate strength of damaged ships in order to facilitate the decision-making process of ship salvage. There are considerable publications on the subject, however, the impact of the induced residual stress and deformation are normally excluded in those studies. This paper therefore aims at investigating the effect of the impact induced residual stress and deformation on the ultimate strength of a stiffened panel through application of a nonlinear Finite Element Analysis (FEA) method. Firstly, a literature review on ultimate strength of damaged ships is presented. Secondly, a nonlinear numerical simulation is adopted to investigate the ultimate strength of stiffened panels accounting for residual stress and deformation. this procedure consists of two stages: the impact stage and the static stage. The results of the numerical simulation of both stages are validated through the results of experiments and simulations available in literature. Afterwards, a series of case studies are performed deploying the validated numerical method. Finally, a closed form expression to predict the ultimate strength accounting for impact induced residual stress and deformation is proposed based on direct simulation. Results show that the combined effect of impact induced residual stress and deformation can significantly reduce structures’ load carrying capacity. The maximum reduction ratio reaches 37% in local stiffened panel. The method of removal of all the plastic deformation area is generally too conservative to predict the ultimate strength of a damaged local stiffened panel, which will underestimate the residual load carrying capacity of ships considerably.

Experimental and numerical investigation on ultimate strength of four-legged latticed columns

2021 ◽  
pp. 136943322110015
Author(s):  
Yinqi Li ◽  
Feng Liu ◽  
Wenming Cheng ◽  
Huasen Liu
Keyword(s):  
Ultimate Strength ◽  
Structural Engineering ◽  
Analytical Techniques ◽  
Experimental Tests ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Compressive Loads ◽  
Initial Geometric Imperfections ◽  
Combined Data ◽  
Loading Eccentricity

Latticed built-up columns are applied more extensively than solid columns in structural engineering because of their excellent load-carrying capacity and light weight. Studies on the bearing capacity of latticed columns, particularly multiple-legged latticed columns, need to be conducted in detail. In this investigation, seven four-legged latticed column specimens of different bar sections, bar distributions and loading eccentricities under compressive loads were subjected to experimental tests. The initial geometric imperfections of the legs and bars were measured and introduced into the FE numerical method. The experimental results were then compared with those of Geometrical and Material Non-Linear Analysis with Imperfection in ABAQUS software. The combined data indicate that the bar section, bar distribution and loading eccentricity significantly influenced the ultimate strength of four-legged latticed columns, producing maximum variations of 105.67%, 65.7% and 48.48%, respectively. This investigation demonstrates the influence of lacing bars and improves the results obtained from FE numerical analytical techniques.

scholarly journals Performance of composite reinforced short column under axial loading

2018 ◽  
Vol 7 (3) ◽  
pp. 1376
Author(s):  
N Chaitanya ◽  
V Ranga Rao ◽  
M Achyutha Kumar Reddy
Keyword(s):  
Axial Loading ◽  
Element Model ◽  
Strain Gauges ◽  
Load Carrying Capacity ◽  
Short Column ◽  
Equal Angle ◽  
Short Columns ◽  
Load Carrying ◽  
Strain Stress ◽  
Loaded Column

The purpose of this paper is to compare the behaviour of composite reinforced concrete square short columns and conventional square short column. Experiments are conducted on four axially loaded column specimens till failure. Among four specimens, two are conventional and remaining two columns are having equal angles as main reinforcement. Short columns are designed using IS 456 2000. The obtained details of main reinforcement are replaced in area wise by equal angle (ISA 2525). The tie reinforcement used to withhold the main reinforcement in position are retained with the same deformed bars. Performance of columns are measured in terms of load carrying capacity, longitudinal strain, stress, crushing modes, strains in each face using strain gauges. Outcome of the experiments are compared and plotted in the form of stress vs strain of the column. A finite element model was developed using Abaqus to simulate the results.  

scholarly journals The Assessment of Using CFRP to Enhance the Behavior of High Strength Reinforced Concrete Corbels

2021 ◽  
Vol 28 (1) ◽  
pp. 71-83
Author(s):  
Mazin Abdulrahman ◽  
Shakir Salih ◽  
Rusul Abduljabbar
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Load Capacity ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Ultimate Load Capacity ◽  
Load Carrying ◽  
Externally Bonded ◽  
Effective Depth

In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6) by 31.25% and 58.69% in cracking and ultimate loads respectively Using CFRP .

Full-Scale Experiments and Analyses of Cellular Hull Sections in Compression

1996 ◽  
Vol 118 (3) ◽  
pp. 232-237 ◽  
Author(s):  
R. J. Dexter ◽  
J. M. Ricles ◽  
L.-W. Lu ◽  
A. A.-K. Pang ◽  
J. E. Beach
Keyword(s):  
Yield Stress ◽  
Ultimate Load ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Compression Tests ◽  
Plate Buckling ◽  
Critical Stresses ◽  
Collapse Strength ◽  
Load Carrying ◽  
Multiple Cell

Compression tests were conducted on high-strength single-cell and multiple-cell box sections with plate width-to-thickness (b/t) ratios ranging from 48 to 96. Local plate buckling occurred at stresses as low as 5 percent of the yield stress, whereas the ultimate compression stress ranged from 38 to 72 percent of the yield stress. These critical stresses were not significantly affected by the length of the specimen, the number of cells, the boundary conditions, or lateral load. Simple empirical design equations based only on b/t gave estimates of the collapse strength within five percent in all cases. Finite-element analyses were able to predict the significant reserve load-carrying capacity and ductility after ultimate load, which was dependent on the length of the specimen as well as the b/t ratio.

Investigation on the Post-Ultimate Strength Behaviour of Damaged Stiffened Plate of Ship Structure

2016 ◽  
Author(s):  
Weijun Xu ◽  
Minjie Yuan ◽  
Xiaotian Wang
Keyword(s):  
Ultimate Strength ◽  
Carrying Capacity ◽  
Crack Depth ◽  
Plate Thickness ◽  
Longitudinal Crack ◽  
Load Carrying Capacity ◽  
Stiffened Plate ◽  
Ship Structure ◽  
Plate Length ◽  
Load Carrying

Post-ultimate strength behaviour of ship structure can directly reflect its changing tendency of load carrying capacity. When the external load exerted on the ship structure exceeds the ultimate strength, sharply reduction of load carrying capacity will occur, especially for the damaged ship structure induced from grounding or collision. This paper focuses on the investigation on the post-ultimate strength behaviour of damaged stiffened plate of ship structure by using FEM, a series of stiffened plate modeling with different kinds of cracks are constructed. The parameters of crack includes length, width, depth, plate thickness and distribution direction. The post-ultimate strength behaviour of stiffened plate with cracks and intact ones are compared. Conclusion can be drawn as follows: (1) crack can induce the reduction of ultimate strength of stiffened plate, meanwhile, the stiffness and its load carrying capacity decrease accordingly. (2) in terms of stiffened thin plate, length of crack has a significant influence on the post-ultimate strength behaviour, the width of the crack has a huge influence on ultimate strength while the depth of crack has little influence; in terms of stiffened thick plate, the influence of crack depth on the post-ultimate strength behaviour becomes obvious. The width of the crack influence the post-ultimate strength behaviour a lot. (3) compare to the transverse crack, the influence of longitudinal crack on the post-ultimate strength behaviour is not obvious.

Sign in / Sign up

Export Citation Format

Share Document