scholarly journals An Analytical Approach for Deformation Shapes of a Cylindrical Shell with Internal Medium Subjected to Lateral Contact Explosive Loading

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiangyu Li ◽  
Zhenduo Li ◽  
Minzu Liang
Keyword(s):  
Cylindrical Shell ◽  
Explosive Charge ◽  
Analytical Approach ◽  
Plastic Hinge ◽  
Experimental Results ◽  
Rigid Plastic ◽  
Lateral Contact ◽  
Internal Medium ◽  
Contact Explosion ◽  
Spring Force

An experimental investigation on deformation shape of a cylindrical shell with internal medium subjected to lateral contact explosion was carried out briefly. Deformation shapes at different covered width of lateral explosive were recovered experimentally. Based on the experimental results, a corresponding analytical approach has been undertaken with rigid plastic hinge theory. In the analytical model, the cylindrical shell is divided into end-to-end rigid square bars. Deformation process of the cylindrical shell is described by using the translations and rotations of all rigid square bars. Expressions of the spring force, buckling moment, and deflection angle between adjacent rigid square bars are conducted theoretically. Given the structure parameters of the cylinder and the type of the lateral explosive charge, deformation processes and shapes are reported and discussed using the analytical approach. A good agreement has been obtained between calculated and experimental results, and thus the analytical approach can be considered as a valuable tool in understanding the deformation mechanism and predicting the deformation shapes of the cylindrical shell with internal medium subjected to lateral contact explosion. Finally, parametric studies are carried out to analyze the effects of deformation shape, including the covered width of the lateral explosive, explosive charge material, and distribution of initial velocity.

The Study of LEFP Based on One Part of Semicircle Liner

2013 ◽  
Vol 753-755 ◽  
pp. 1625-1629
Author(s):  
Jie Liu ◽  
Zhong Hua Du ◽  
Rong Zhong Liu ◽  
Yu Cai Dong
Keyword(s):  
Linear Equation ◽  
Explosive Charge ◽  
Analytical Approach ◽  
Experimental Results ◽  
Two Dimensional ◽  
X Ray ◽  
Axis Direction ◽  
Test Velocity ◽  
Relationship Of ◽  
The Relationship

In order to obtain the forming and the velocity of LEFP(Linear Explosively Formed Penetrators) based on one part of semicircle liner, the X-ray radiography and test velocity technology are used to obtain the forming and velocity of LEFP. In this paper, an analytical approach to describe the two-dimensional liner motion of LSCs is addressed firstly at a detonation-point. The relationship of LEFP flight distance can approximate a linear equation to estimate the distance of LEFP before contacting target. Experimental results showed that the shape of LEFP likes a scimitar according to gray image, and LEFP can close around linear explosive charge length axis direction.

Stresses in compact end closures for cylindrical pressure vessels

1969 ◽  
Vol 4 (1) ◽  
pp. 57-64
Author(s):  
R W T Preater
Keyword(s):  
Cylindrical Shell ◽  
Rigid Body ◽  
Optimum Design ◽  
Cross Section ◽  
Experimental Verification ◽  
Pressure Vessels ◽  
Rigid Body Motion ◽  
Experimental Results ◽  
Body Motion ◽  
Annular Ring

Three different assumptions are made for the behaviour of the junction between the cylindrical shell and the end closure. Comparisons of analytical and experimental results show that the inclusion of a ‘rigid’ annular ring beam at the junction of the cylider and the closure best represents the shell behaviour for a ratio of cylinder mean radius to thickness of 3–7, and enables a prediction of an optimum vessel configuration to be made. Experimental verification of this optimum design confirms the predictions. (The special use of the term ‘rigid’ is taken in this context to refer to a ring beam for which deformations of the cross-section are ignored but rigid body motion is permitted.)

scholarly journals Representative Stress Correlation of Global Scratch Quantities at Scratch Testing: Experimental Verification

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 154
Author(s):  
Per-Lennart Larsson
Keyword(s):  
Polymeric Materials ◽  
Experimental Results ◽  
Scratch Testing ◽  
Rigid Plastic ◽  
Viscoelastic Effects ◽  
Elasto Plasticity ◽  
The Difference ◽  
Von Mises ◽  
Experimental Findings ◽  
Static Conditions

Evaluation and correlation of global quantities, i.e., normal and tangential hardness, at scratch testing in the context of a representative stress description was investigated. In particular, verification based on experimental results is at issue. It has been shown previously that within the framework of classical von Mises elasto-plasticity and quasi-static conditions, correlation can be achieved by using a combination of stresses at different levels of plastic strains to define representative quantities at scratching, accounting for the difference in mechanical behavior at elasto-plastic and rigid plastic scratching. However, verification from experimental results is required, which has been attempted in this study. Predictions based on previous theoretical results were compared with experimental findings for polymeric materials, as well as for different metals. Good agreement was found between the two sets of results, particularly so for the case of polymers modelled by von Mises elasto-plasticity. Accordingly, these results are of direct practical, accurate, and novel relevance for semi-crystalline polymers where viscoelastic effects are negligible.

scholarly journals Parametric Analysis on Seismic Performance of Hybrid Precast Concrete Beam-Column Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
H.-K. Choi ◽  
Grzegorz Golewski
Keyword(s):  
High Performance ◽  
Precast Concrete ◽  
Plastic Hinge ◽  
Cement Composite ◽  
Fe Analysis ◽  
Experimental Results ◽  
Critical Parameters ◽  
Detailed Model ◽  
Plate Length ◽  
Bolt Stress

In this paper, a nonlinear finite element (FE) analysis of high-performance hybrid system (HPHS) beam-column connections is presented. The detailed experimental results of the ten half-scale hybrid connections with limited seismic detailing have been discussed in a different paper. However, due to the inherent complexity of HPHS beam-column joints and the unique features of the tested specimens, the experimental study was not comprehensive enough. The new connection (HPHS) detail suggested in this study is characterized by ductile connection, steel connectors, and engineered cementitious composite (ECC) which is a kind of high-performance fiber reinforced cement composite with multiple fine cracks (HPFRCCs). Therefore, in this paper, FE analysis results are compared with experimental results from the cycle tests of the two specimens (RC and PC) to assess model accuracy, and detailed model descriptions are presented, including the determination of stiffness and strength. The critical parameters influencing the joint’s behavior are the axial load on column, beam connection steel plate length, inner bolt stress contribution, and plastic hinge area.

An Approximate Model for an Elastic-Plastic Pipe Element Under Combined Loading

1975 ◽  
Vol 97 (1) ◽  
pp. 22-28 ◽  
Author(s):  
L. D. Larson ◽  
W. F. Stokey ◽  
W. E. Franzen
Keyword(s):  
Strain Hardening ◽  
Axial Load ◽  
Analytical Approach ◽  
Limit Load ◽  
Approximate Model ◽  
Experimental Results ◽  
Combined Loading ◽  
Elastic Plastic ◽  
Plastic Pipe ◽  
Plastic Analysis

An approximate model for the elastic-plastic analysis of a pipe element under combined loading is developed. The model is obtained by generalizing a limit load solution for combined pressure, bending, torsion and axial load to include strain hardening. For various combinations of loading of tubes, curvatures and twist angles are predicted and compared with experimental results and those predicted by a more rigorous analytical approach. The comparison shows that good results are obtained from the approximate model.

Experimental Study on Deformation and Shock Damage of Cylindrical Shell Structures Subjected to Underwater Explosion

2010 ◽  
Vol 224 (11) ◽  
pp. 2505-2514 ◽  
Author(s):  
L-J Li ◽  
W-K Jiang ◽  
Y-H Ai
Keyword(s):  
Cylindrical Shell ◽  
Underwater Explosion ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Shell Structures ◽  
Security Evaluation ◽  
Wave Loading ◽  
Shell Models ◽  
Edge Cracks ◽  
Damage Condition

The security evaluation of some structures shocked by an underwater explosion (UNDEX) frequently plays a key role in some cases, and it is necessary to accurately predict the damage condition of the structure in an UNDEX environment. This study investigates the dynamic linear and non-linear responses and shock damages of two kinds of submerged cylindrical shell models exposed to underwater spherical trinitrotoluene (TNT) charge explosions in a circular lake. Two endplates and a middle plate are mounted on the cylindrical shells to provide support and to create two enclosed spaces. The two kinds of cylindrical shell models with the same geometry characteristics are unfilled and main hull sand-filled. Fifteen different tests are carried out by changing the TNT explosive weights of 1 and 2 kg, standoff distances ranging from 3 to 0.3 m, and two explosion positions. Measured experimental results are compared with each other, and some transformed data are obtained. A detailed discussion on experimental results shows that the dynamic responses and damage modes are much different, and the main hull sand-filled cylindrical shell is more difficult to be damaged by the shock wave loading than the unfilled model. Edge cracks are mainly observed at the instrument hull of the main hull sand-filled model, but surface tearing and cracks are observed on both the main hull and the instrumental hull of the unfilled model, respectively.

Dynamic Response of a Cylindrical Shell in a Potential Fluid

1979 ◽  
Vol 46 (4) ◽  
pp. 772-778 ◽  
Author(s):  
G. E. Cummings ◽  
H. Brandt
Keyword(s):  
Cylindrical Shell ◽  
Dynamic Response ◽  
Circular Cylindrical Shell ◽  
Time History ◽  
Experimental Results ◽  
Scale Model ◽  
Solution Technique ◽  
Analytical Technique ◽  
Forcing Function ◽  
Potential Fluid

A numerical solution technique is presented for determining the dynamic response of a thin, elastic, circular, cylindrical shell of constant wall thickness and density, in a potential fluid. The shell may be excited by any radial forcing function with a specified time history and spatial distribution. In addition, a pressure history may be specified over a segment of the fluid outer boundary. Any of the natural shell end conditions may be prescribed. The numerical results are compared to experimental results for a 1/12-scale model of a nuclear-reactor core-support barrel. Natural frequencies and modes are determined for this model in air, water, and oil. The computed frequencies are within 15 percent of experimental results. A sample application compares the numerical technique to an analytical solution for shell beam modes. The comparison resolves an uncertainty concerning the proper effective mass to use in the analytical technique.

The impact torsional buckling for the rigid plastic cylindrical shell

1993 ◽  
Vol 14 (8) ◽  
pp. 693-698 ◽  
Author(s):  
Wang De-yu ◽  
Zhang Shan-yuan ◽  
Yang Gui-tong
Keyword(s):  
Cylindrical Shell ◽  
Rigid Plastic ◽  
Torsional Buckling ◽  
Plastic Cylindrical Shell ◽  
The Impact

Explicit formulation for the axial collapse of a pipe during drilling

2010 ◽  
Vol 224 (8) ◽  
pp. 1547-1549
Author(s):  
A Almasi
Keyword(s):  
Closed Form ◽  
Plastic Hinge ◽  
Variable Length ◽  
Experimental Results ◽  
Displacement Curve ◽  
Explicit Formulation ◽  
Theoretical Predictions ◽  
Hinge Zone ◽  
Good Agreement

New closed-form expressions are introduced for ax-symmetric progressive axial collapse of pipes that use a plastic folding mechanism based on variable length of an active plastic hinge zone. A procedure for determination of a load—displacement curve of axial pipe collapse is presented. Theoretical predictions give a good agreement with the experimental results owing to the influence of presented new refinements.

Buckle Propagation Analysis of Deep-Water Petroleum Transmission Pipelines with Axial Tension

2014 ◽  
Vol 1008-1009 ◽  
pp. 1134-1143 ◽  
Author(s):  
Sun Ting Yan ◽  
Yin Fa Zhu ◽  
Zhi Jiang Jin ◽  
Hao Ye
Keyword(s):  
Plastic Hinge ◽  
External Pressure ◽  
Isotropic Hardening ◽  
Rigid Plastic ◽  
Perfectly Plastic ◽  
Fitting Procedure ◽  
Plastic Materials ◽  
Buckle Propagation ◽  
Elastic Perfectly Plastic ◽  
Hinge Model

Quasi-static finite element simulation is carried out on buckle propagation phenomenon of offshore pipelines under external pressure. Arc-length method and volume-controlled static analysis by employing hydrostatic fluid element F3D4 are employed to calculate the steady buckle propagation pressure. After verifying the validity of numerical model, emphasis is on the influence of tension on propagation pressure considering isotropic hardening elastoplastic and elastic-perfectly plastic materials. Parametric study is conducted to include the effect of diameter-thickness ratio, after which two empirical equations are derived by curve fitting procedure. Finally, some comments on the results obtained through rigid-plastic hinge model are presented and a modified plastic hinge model including effect of material anisotropy is derived. The results can serve as a reference for more reasonable design of buckle arrestors.

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