scholarly journals A Dynamic Cavity Expansion Model for Rigid Projectile Penetration into Concrete considering the Compressibility and Nonlinear Constitutive Relations

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fei Gao ◽  
Zhen Wang ◽  
Zhu Wen ◽  
Yuguo Ji
Keyword(s):  
Yield Criterion ◽  
Constitutive Relations ◽  
Cavity Expansion ◽  
Depth Of Penetration ◽  
Proposed Model ◽  
Rigid Projectile ◽  
Calculation Results ◽  
Expansion Model ◽  
Constitutive Parameters ◽  
Nonlinear Constitutive Relations

The P-α equation of state (EOS) and a nonlinear yield criterion are utilized to characterize the dynamic constitutive behavior of concrete targets subjected to projectile normal penetration. A dynamic cavity expansion model considering the compressibility and nonlinear constitutive relations for concrete material is developed. Then, a theoretical model to calculate the depth of penetration (DOP) for rigid projectile is established. Furthermore, the proposed model is validated based on the available test data as well as the calculation results by the linear compressible EOS and linear yield criterion. This study shows that the proposed model derived using the P-α EOS and nonlinear yield criterion can effectively reflect the plastic mechanical properties of concrete and is also suitable for predicting the DOP of concrete targets. In addition, the influence law of concrete constitutive parameters such as the cohesion strength, shear strength, internal friction coefficient, and elastic limit pressure on the DOP is revealed.

Theoretical Analysis of Dynamic Spherical Cavity Expansion in Reinforced Concretes

2016 ◽  
Vol 715 ◽  
pp. 222-227 ◽  
Author(s):  
Shuang Zhang ◽  
Hai Jun Wu ◽  
Zheng Jun Tan ◽  
Feng Lei Huang
Keyword(s):  
Reinforced Concrete ◽  
Theoretical Analysis ◽  
Spherical Cavity ◽  
Yield Criterion ◽  
Cavity Expansion ◽  
Physical Parameters ◽  
Depth Of Penetration ◽  
Dilation Equation ◽  
Comparison Results ◽  
Spherical Cavity Expansion

This paper aims to establish a model that considers the penetration resistance caused by the constraint effects of steel reinforcements on concrete. Firstly, based on the experiment phenomena that reinforcements increase the toughness and tensile strength of concretes, the fitting relational expression between toughness of reinforced concrete and ratio of reinforcement was used to improve the Griffith yield criterion for reinforced concrete. Then, the dynamic spherical cavity expansion analysis was developed using the improved Griffith yield criterion as constitutive model and the dilation equation as equation of state, and the response regions were consisted of six distinct zones: cavity, compaction zone, dilation zone, radially cracked zone, elastic zone and undisturbed zone. This dynamic analysis considered the compression and dilation of concretes at the same time and was applicable to the penetration problem of reinforced concrete target. At last, based on the theoretical model of this paper, the experiments of projectiles with different weights penetrating into reinforced concrete targets with different reinforcement ratios were calculated using penetration analysis method of rigid projectiles. The comparison results showed that the theoretical analysis model of this paper can be used to predict the depth of penetration and other physical parameters such as velocity and deceleration with certain rationality.

A Cracked-Comminuted Model for Penetration into Confined Concrete Targets

2013 ◽  
Vol 357-360 ◽  
pp. 839-843 ◽  
Author(s):  
Ming Zhen ◽  
Dian Yi Song ◽  
Zhi Gang Jiang
Keyword(s):  
Yield Criterion ◽  
Volumetric Strain ◽  
Confined Concrete ◽  
Cavity Expansion ◽  
Small Radius ◽  
Expansion Velocity ◽  
Low Velocity ◽  
Cylindrical Cavity Expansion ◽  
Strain Relationship ◽  
Expansion Model

Confined concrete is superior to the normal concrete in anti-projectile performance. The concrete filled confining tube of relatively small radius would be in cracked-comminuted stage during the penetrating process of projectiles at relatively low velocity. Based on the linear pressure-volumetric strain relationship and the Mohr-Coulomb yield criterion, a dynamic cylindrical cavity expansion model for the penetration into confined concrete targets with lateral elastic confinement is proposed. Numerical results show that the lateral confinement improves cavity stress significantly, and the radius ratio of target to cracked-comminuted interface has little influnce on cavity stress for relatively low cavity expansion velocity.

Dynamic finite cylindrical cavity-expansion models for cellular steel tube confined concrete targets normally impacted by rigid sharp-nosed projectiles

2021 ◽  
pp. 204141962110272
Author(s):  
Chaomei Meng ◽  
Dianyi Song ◽  
Qinghua Tan ◽  
Zhigang Jiang ◽  
Liangcai Cai ◽  
...  
Keyword(s):  
Cylindrical Cavity ◽  
Approximate Model ◽  
Steel Tube ◽  
Confinement Effect ◽  
Confined Concrete ◽  
Cavity Expansion ◽  
Depth Of Penetration ◽  
Cylindrical Cavity Expansion ◽  
Infinite Cylindrical Shell ◽  
Response Modes

Cellular steel-tube-confined concrete (CSTCC) targets show improved anti-penetration performance over single-cell STCC targets due to the confinement effect of surrounding cells on the impacted cell. Dynamic finite cylindrical cavity-expansion (FCCE) models including radial confinement effect were developed to predict the depth of penetration (DOP) for CSTCC targets normally penetrated by rigid sharp-nosed projectiles, and stiffness of radial confinement was achieved with the elastic solution of infinite cylindrical shell in Winkler medium. Steady responses of dynamic FCCE models were obtained on the assumption of incompressibility of concrete, failure of comminuted zone with Heok–Brown criterion and two possible response modes of the confined concrete in the impacted cell. Furthermore, a DOP model for CSTCC targets normally impacted by rigid projectiles was also proposed on the basis of the dynamic FCCE approximate model. Lastly, relevant penetration tests of CSTCC targets normally penetrated by 12.7 mm armor piecing projectile (APP) were taken as examples to validate the dynamic FCCE models and the corresponding DOP model. The results show that the DOP results based on dynamic FCCE model agree well with those of the CSTCC targets normally penetrated by rigid conical or other sharp-nosed projectiles.

A Least Cost Transmission Planning Model Considering Operation Cost

2014 ◽  
Vol 15 (2) ◽  
pp. 121-128
Author(s):  
Jorge Hans Alayo
Keyword(s):  
Test System ◽  
Mixed Integer ◽  
Transmission Planning ◽  
Integer Linear Programming Problem ◽  
Transmission Expansion ◽  
Planning Models ◽  
Proposed Model ◽  
Expansion Model ◽  
Operation Cost ◽  
Linearization Techniques

Abstract Existing transmission planning models consider basic aspects of the problem. In practice, a transmission utility needs to model other important details such as operation cost of the power system. In this article, a least cost transmission expansion model is proposed considering the operation cost in order to model the trade-off between building new transmission capacity and increasing the power system’s operation cost. The proposed model is transformed into a mixed integer linear programming problem using linearization techniques and solved with CPLEX. Finally, results of the model for the Garver test system and IEEE 24-bus test system are shown.

Tribological Behavior of a Thermoplastic Material Under the Action of a Conic Penetrator in Sliding Movement

2021 ◽  
Vol 58 (1) ◽  
pp. 27-33
Author(s):  
Ivona Camelia Petre ◽  
Elena Valentina Stoian ◽  
Maria Cristiana Enescu
Keyword(s):  
Tribological Behavior ◽  
Kinetic Friction ◽  
Depth Of Penetration ◽  
Thermoplastic Material ◽  
Knowing How ◽  
Metal Material ◽  
Proposed Model

Knowing how to deform the Turcite thermoplastic material under the action of conical penetrators is a means of obtaining information on the processing of the counterpart (made from a metal material with higher hardness) with which it comes into contact.The paper aims to theoretically determine the depth of penetration of the thermoplastic material under the action of some conical penetrators and to establish the coefficient of static and kinetic friction under the action of these penetrators. The proposed model will be validated experimentally on a tribological stand made for this purpose.

Evolutive Laws and Constitutive Relations in Nonlocal Viscoplasticity

2012 ◽  
Vol 152-154 ◽  
pp. 990-996 ◽  
Author(s):  
Fabio de Angelis
Keyword(s):  
Constitutive Relations ◽  
Material Model ◽  
Standard Material ◽  
Viscoplastic Model ◽  
Proposed Model

In the present work the evolutive laws and the constitutive relations for a model of nonlocal viscoplasticity are analyzed. Nonlocal dissipative variables and suitable regularization operators are adopted. The proposed model is developed within the framework of the generalized standard material model. Suitable forms of the elastic and dissipative viscoplastic potentials are defined and the associated constitutive relations are specialized. The evolutive laws for the proposed nonlocal viscoplastic model are presented in a general form which can be suitably specialized in order to include different models of nonlocal viscoplasticity.

A Hystersis Model for Piezoceramic Materials

1999 ◽  
Author(s):  
Ralph C. Smith ◽  
Zoubeida Ounaies
Keyword(s):  
Electric Fields ◽  
High Performance ◽  
Constitutive Relations ◽  
Domain Wall Motion ◽  
Full Potential ◽  
Ode Model ◽  
Performance Control ◽  
High Drive ◽  
Nonlinear Constitutive Relations ◽  
Control Implementation

Abstract This paper addresses the modeling of nonlinear constitutive relations and hysteresis inherent to piezoceramic materials at moderate to high drive levels. Such models are necessary to realize the full potential of the materials in high performance control applications, and a necessary prerequisite is the development of techniques which permit control implementation. The approach employed here is based on the quantification of reversible and irreversible domain wall motion in response to applied electric fields. A comparison with experimental data illustrates that because the resulting ODE model is physic-based, it can be employed for both characterization and prediction of polarization levels throughout the range of actuator operation. Finally, the ODE formulation is amenable to inversion with facilitates the development of an inverse compensator for linear control design.

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