the support of the ministry of science and higher education under the grant s

THE SUPPORT OF THE MINISTRY OF SCIENCE AND HIGHER EDUCATION UNDER THE GRANTSN519-419435 AND R00-0097-12 IS KINDLY ACKNOWLEDGEDwww.put.poznan.plhttp://www.cmm.il.pw.edu.pl/

Outline:

- Motivation- Introductory remarks- Objectives and numerical analysis:- Structural safety- Public safety- Results- Conclusionshttp://www.cmm.il.pw.edu.pl/THE SUPPORT OF THE MINISTRY OF SCIENCE AND HIGHER EDUCATION UNDER THE GRANTSN519-419435 AND R00-0097-12 IS KINDLY ACKNOWLEDGED

Motivation: The elements of critical infrastructure are often under explosive risk, and must be protected- Airports- Railway Stations- Trade & Business centers- Banks- Fuel depots and storages- Government agencies

Objective: Pressure distribution and structural damage

Introductory Remarks:

- The office structure (the main structure) is subjected to explosion

- The analysis demands a compelx caluculations (complexity, dof). This time the general problem of safety is uncoupled into three jobs:

A) STRUCTURAL ELEMENT SAFETY (steel column)

B) GLOBAL STRUCURE SAFETY (whole RC structure)

C) PERSONEL SAFETY (pressure evolution)

Introductory Remarks:

Structural safety criteria1. Acceleration for equipment3g, t > 1200s; 5g, t > 60s;8g, t > 10s; 18g, t > 0.2s;25g, t > 0.001s; 60g (database server)2. Stress & Strain for structural elementsDepending on material kind, compression, tension, strain rate, loading peaks and impulses

Public safety criteriaHuman tolerance to the blast output of an explosion is relatively high. However, the orientation of a person (standing, sitting, etc.) is really important. The pressure tolerance for short-duration blast loads is significantly higher than that for long-duration blast loads. There are used two separate criteria, in agreement US standard i.e. Unified Facilities Criteria (UFC 3-340-02), for assessment public safety.

1. Eardrums rupture for overpressure above 40 000 [Pa], and impulse duration 0.2 [Pas]2. Lung damage depends on overpressure-impulse and person weight

Objectives and Numerical Analysis: Structural safety

Case A Steel column

Objective: To find a limit value of scaled distance (Z) for safety design

GeometrySteel column (H-section), IPE300, 3m high, fixed-joint boundariesMaterialJohnson-Cook model for stainless steel [Akbari, Joodaki 2005]Numerical job72e3 S4R elements (0.005x0.005m2), time of the analysis is 52e3s (1CPU 2.6XEON)

1. Initial Static loading (10s)Dominant is vertical force (effort below 90%)2. Explosive loading CONWEP (0.01s)0.1kg of TNT in 0.25m distance3. Assessment of limit loading (10s)Upper boundary movement (1cm/10s)

F0F0F0explosive loading


Case A Steel column

Results IPE300

The results for the 1kg of TNT in 0.25m distance

The FE mesh is decreased in to 0.05 by 0.05 m2 element size


Case A Steel column

Different failure criteria for steel elements


Case A Steel column

Results IPE300 for close (distance


Case A Steel column

Results HEB600 for close explosions (distance


Case B Whole structure

Objective: General assessment of whole structure safety

The explosive pressure is subjected to reinforced concrete structure. The homogenous RC material is loaded by the overpressure.GeometryRC structure 30x30m2 and 20m high (6 floors)MaterialElastic RC concrete with stress limit (FE deletion)Ideal Gas Equation of the state for the Ambient AirJWL Equation of the state for the ExplosiveNumerical jobEOS ~5e6 EC3D8 finite elements (0.2x0.2x0.2m3), Def. ~2e6 C3D8 finite elements (0.1x0.1x0.1m3)Time of the analysis is 26h (8CPU 2.6XEON)

1. Initial Static loading450kg/m22. Explosive loading CEL1000kg of TNT in 2.0m distance form the frontal facade



The results

FE failure criteria

Compression -80.0MPaTension +1.0MPa

t=0.001s after detonation

t= 0.01s after detonation


Case C Public safety

Objective: Overpressure distribution inside a building

GeometryRigid geometry of the building simulates the reflection of the blast wave MaterialIdeal Gas Equation of the state for the Ambient AirJWL Equation of the state for the ExplosiveNumerical job~5e6 C3D8 finite elements (0.2x0.2x0.2m3), time of the analysis is 8h (8CPU 2.6XEON)

1. Initial Static loading450kg/m22. Explosive loading CEL100kg of TNT in 2.0m distance form the frontal facade



The blast wave reflection from the rigid body



Personnel safety criteria (TM5-1300, UFC), for SI units

Lung DamageEar drums rupture



Results The limit value for personnel safety has been set on 250000Pa (grey elements)The blast wave front (>150000Pa) propagates through the structure

Conclusions

A1. Limit values of scaled distance are obtained for steel columns

A2. Scaled distance is different for close and far field explosive action

A3. Further study enforces using of advanced material behavior

B1. Analysis of whole RC structure + steel reinforcement !

B2. Air discretisation vs. the results

C1. Personnel safety is analyzed, what about fragmentation ?

Thank you for your attention !

e-mail: [email protected] [email protected]

Poznan University of Technology

The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.The analysis is performed in Abaqus v6.10 code. The model is IPE300, and it contains 8k S4R finite elements. The material behavior is described by Johnson-Cook model, including the exampled stainless steel properties [Akbari, Joodaki 2005].The explosive loading is simulated by CONWEP tool which allows for prediction of pressure surface on the obstacle. The pressure loading is calculated using the empirical data in which mass, length, time, and pressure evaluate in the time function.

the support of the ministry of science and higher education under the grant s

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