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.

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.

scholarly journals Influence of boundary condition and stiffener type on collapse behaviours of stiffened panels under longitudinal compression

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988476
Author(s):  
Jin Pan ◽  
Na Li ◽  
Zhao Jun Song ◽  
Ming Cai Xu
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Carrying Capacity ◽  
Biaxial Stress ◽  
Stiffened Panel ◽  
Load Carrying Capacity ◽  
Longitudinal Compression ◽  
Stiffened Panels ◽  
Biaxial Stress State ◽  
Load Carrying

A series of stiffened panels with different dimensions and types of stiffener are simulated under longitudinal compression in finite element code ANSYS. Two bays/spans model with periodic boundary condition is adopted to consider the influence of neighbouring members. The stiffened panel adopted in the finite element mode is generally cut from the deck or bottom of a ship hull girder, and thus, the constraint on their edges depends to some extent on the relative structural response of the adjacent members. Hence, to understand the effects of constraint condition on the collapse behaviour, an extensive parametric study is carried out, employing a wide geometrical range for bulk carrier and very large crude carrier. Moreover, considering various collapse modes, the load-carrying capacities of the stiffened panels are also investigated for various stiffener types. It is found that the biaxial stress state caused by longitudinal constraint could increase or decrease the load-carrying capacity of the stiffened panel, which depends on the collapse mode and should be noticed. The transverse constraint on the longitudinal edges could cause biaxial stress state, which might increase or decrease the load-carrying capacity of the stiffened panel, which depends on the collapse modes.

EFFECTS OF CFRP REINFORCEMENTS ON THE BUCKLING BEHAVIOR OF THIN-WALLED STEEL CYLINDERS UNDER COMPRESSION

2012 ◽  
Vol 12 (01) ◽  
pp. 131-151 ◽  
Author(s):  
KRISHNA KUMAR BHETWAL ◽  
SEISHI YAMADA
Keyword(s):  
Carrying Capacity ◽  
Fiber Orientation ◽  
Buckling Analysis ◽  
Load Carrying Capacity ◽  
Buckling Strength ◽  
Frp Composite ◽  
Load Carrying ◽  
Thin Walled ◽  
Multiple Treatments ◽  
Collapse Behavior

This paper presents a novel way of strengthening thin-walled steel cylindrical shells against buckling during axial compression in which a small amount of fiber-reinforced polymer (FRP) composite, coated from both sides can increase the buckling strength effectively. The effects of the reinforcement and the angle of fiber orientation as well as initial geometric imperfections on the buckling load-carrying capacity have been made clear through the three kinds of analytical procedures; the conventional linear eigen value buckling analysis, the reduced stiffness (RS) buckling analysis and the fully nonlinear numerical experiments. These multiple treatments suggest obtaining valuable information for the design of FRP-based hybrid structural elements and discusses influence of FRP to increase the load-carrying capacity of the thin-walled metallic structures having complex buckling collapse behavior. This paper also discusses how the angle of fiber orientation affects on the buckling strength and the associated buckling modes of the thin-walled shells.

scholarly journals Experimental Study on Structural Behaviour of Glulam Beams Pre-stressed by Compressed Wood

2017 ◽  
Vol 2 (1) ◽  
pp. 54-61
Author(s):  
Buan Anshari ◽  
Akihisa Kitamori ◽  
Kiho Jung ◽  
Kohei Komatsu
Keyword(s):  
Carrying Capacity ◽  
Longitudinal Direction ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Structural Behaviour ◽  
Compressive Stresses ◽  
Reinforced Beams ◽  
Load Carrying ◽  
Strength And Stiffness ◽  
Compressed Wood

This paper presents the study on structural behaviour of glulam beams pre-stressed by compressed wood (CW) in terms of load carrying capacity, strength and stiffness. Glulam beams were strengthened by inserting CW blocks into the pre-cut rectangular holes on the top of the beams. This practice was to make use of moisture-dependent swelling nature of the compressed wood. The CW block was placed in a way in which its radial direction was coincident with the longitudinal direction of the beam to be strengthened. After pre-stressing process, all beams were placed in a chamber with Relative Humidity (RH) fluctuated between 40% until 80% and a constant temperature of 20⁰C until the maximum swelling of the CW block was reached. The glulam beams with the size of 3800 mm long, 200 mm deep and 120 mm wide were reinforced by 3, 5, 7 CW blocks respectively, all with the same thickness of 45 mm. In addition, there were two beams which were reinforced at the bottom extreme fibre with one lamella made of compressed wood. There were also three beams without any reinforcement for control purpose. The test results showed that a pre-camber was produced in the mid-span of the beam reinforced. At both the top and the bottom extreme fibres of the beam significant initial tensile and compressive stresses were generated respectively. Bending tests indicated that the load carrying capacity of the reinforced beams increased significantly in comparison to the beam without reinforcement. 

scholarly journals Experimental Research on Equivalent Rectangular Opening Castellated Beam with Fillet Corner

2020 ◽  
Vol 8 (5) ◽  
pp. 5415-5420
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Rectangular Section ◽  
Flexure Mechanism ◽  
Modes Of Failure ◽  
Load Carrying ◽  
Shear Buckling ◽  
Castellated Beam

Nowadays the use of castellated beam has been admired due to its beneficial functions like a light in weight, easy to erect, economical and stronger. The castellated beam is manufactured from its parent solid I beam by cutting it in a zigzag pattern and again joining it by welding so that the depth of the beam increases. Hence, due to an increase in depth of beam load carrying capacity of the parent I section is increased with the same quantity of material and weight. The increase in depth of the castellated beam leads to web post-buckling and lateral-torsional buckling failure when these beams are subjected to loading. There are many other modes of failure like the formation of flexure mechanism, lateral-torsional buckling, and formation of Vierendeel mechanism, rupture of the welded joint in a web post and shear buckling of a web post which needs to be taken care of. Hence, in the present paper, an attempt has been made to evaluate existing literature, concerned with the strength of the beam by providing a rectangular opening and rectangular opening equivalent to diagonal & hexagonal opening with different angles of opening 300 , 450 & 600 . The fillet radius is provided to the corner of the rectangular opening as a result of a 54% increase in the load-carrying capacity of the rectangular section compared to the regular rectangular section.

Plastic Collapse of API 5L X65 Pipe Having Dent Defects Under Internal Pressure and Bending Load

2010 ◽  
Author(s):  
Jong-hyun Baek ◽  
Young-pyo Kim ◽  
Cheol-man Kim ◽  
Woo-sik Kim ◽  
Jae-mean Koo ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Plastic Collapse ◽  
Load Carrying Capacity ◽  
Combined Load ◽  
Bending Mode ◽  
Load Carrying ◽  
Collapse Behavior ◽  
Dent Depth

The objective of this study was to investigate the effect of the dent magnitude on the collapse behavior of dented pipe subjected to a combined internal pressure and in-plane bending. The plastic collapse behavior and bending moment of the dented pipe with several of dent dimensions were evaluated by using elastic–plastic finite element (FE) analyses. The indenters used to manufacture the dents on the API 5L X65 pipe were hemispherical rod type with diameter of 40, 80, 160 and 320 mm. Dent depths of 19, 38, 76, 114 and 152 mm were introduced on the pipe having a diameter of 762 mm and a wall thickness of 17.5 mm in analyses. A closing or opening inplane bending moment was applied on the dented pipes pressurized under internal pressure of the atmospheric pressure, 4, 8 and 16 MPa. The FE analyses results showed that the plastic collapse behavior of dented pipes was considerably governed by the bending mode and the dent geometry. Moment-bending angle curves for dented pipe were obtained from computer simulation and evaluated with a variety of factors in FE analyses. Load carrying capacity of dented pipes under combined load was evaluated by TES (Twice Elastic Slope) moments. Load carrying capacity of pipe having up to 5% dent depth of outer diameter was not reduced compared with that of plain pipe. Opening bending mode had a higher load carrying capacity than closing bending mode under combined load regardless of dent depth. TES moment was decreased with increasing the dent depth and internal pressure regardless of bending modes.

Integral Strain Gauges Application for Gearing Reliability Estimation

2017 ◽  
Vol 906 ◽  
pp. 44-49
Author(s):  
Vladimir Syzrantsev ◽  
Ksenia Syzrantseva
Keyword(s):  
Carrying Capacity ◽  
Reliability Estimation ◽  
Field Conditions ◽  
Strain Gauges ◽  
Load Carrying Capacity ◽  
Short Term ◽  
Basic Principles ◽  
Load Carrying ◽  
Gear Box

The paper describes the basic principles and some results of obtaining data by means of integral strain gauges about load-carrying capacity and durability of gear transmissions for new specimens of machines when running in the transmissions in structure of gear box on the stand, or in short-term trials of machines in field conditions.

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.

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