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Article
Publication date: 1 October 2020

Osama Bedair

This paper reviews engineering work developed for blast analysis and design of industrial/residential and ammunition storage facilities. The review also covers work done for…

Abstract

Purpose

This paper reviews engineering work developed for blast analysis and design of industrial/residential and ammunition storage facilities. The review also covers work done for progressive collapse analysis and blast deflectors.

Design/methodology/approach

The first part of the paper describes characteristics of various types of explosions. Empirical and numerical models that were developed to estimate structural capacity are reviewed. The structural idealization, theoretical basis, and merits of various methods are also described. The influence of various parameters affecting the structural performance is discussed.

Findings

The material of the paper captures recent engineering developments that can be used by practitioners for blast analysis and design for industrial and residential buildings. Little emphasis was given in the published literature to develop simplified analytical models that can be used in practice to compute the dynamic response of buildings subject to accidental explosions. Furthermore, analytical expressions are required to compute the reduction in the stiffness due to impact loading.

Originality/value

Current building codes address conventional live, dead, wind and earthquake loads. Very few guidelines are available in practice for design of buildings subject to blast loading. The objective of this paper is to review and piece together recent engineering work developed for blast analysis and design of industrial/residential buildings and ammunition facilities. The paper provides useful resource material for the engineers in practice using recent techniques to design these structures. The review covers past three decades that can be used as a baseline for future developments.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 29 April 2021

Osama Bedair

The purpose of this paper is to describe cost effective structural design procedures to support catalytic reactors used in hydrocarbon industry. Three case studies are presented…

Abstract

Purpose

The purpose of this paper is to describe cost effective structural design procedures to support catalytic reactors used in hydrocarbon industry. Three case studies are presented using various reactor models. Modularization and transportation challenges are also discussed. The scope of the paper is limited only to the structural and construction aspects. The chemical and mechanical designs are not covered in this paper.

Design/methodology/approach

Finite element strategies are developed to model load transfer to reactor’s supports and to simulate soil/structure interaction. Fictitious nodes are generated at bolt locations to transfer the reactor’s loadings from the skirt to the pile cap. Soil-pile interaction is modeled using horizontal and vertical springs along the pile embedded length. Flexible supports are used at the bottom of the piles to stimulate the end bearing of the soil bed. The approach is demonstrated for several case studies of reactors support system.

Findings

The described algorithm is accurate and computationally efficient. Furthermore, the procedure can be used in practice for design catalytic reactor support.

Practical implications

The paper provides very useful guidelines that can be utilized in practice for design of catalytic reactor supports system. The procedure is cost effective and computationally efficient.

Originality/value

Extensive efforts were made in the past to develop economical procedures for catalytic reactors design. Much of the work focused on the process and mechanical aspects of catalytic reactors. Very limited work addressed the structural design aspects. Furthermore, no guidelines are available in current codes of practice.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 24 April 2020

Osama Bedair

In this work, a numerical algorithm is presented for stability analysis of cold-formed steel (CFS) channel sections.

Abstract

Purpose

In this work, a numerical algorithm is presented for stability analysis of cold-formed steel (CFS) channel sections.

Design/methodology/approach

A nonlinear optimization problem is formulated using energy-based technique of idealized channel section subject shear, compression and biaxial bending. The total potential energy is minimized with respect to skew angle and half wavelength of the buckling mode. The optimization algorithm is updated sequentially using quadratic approximation until minimum buckling coefficient is attained. The developed algorithm is validated using other numerical techniques.

Findings

The described algorithm is computationally effective and can be utilized in the industry for analysis of CFS channels under any load combination.

Practical implications

The paper offers a new tool for engineers in practice to analyze channels subject to combined loadings.

Originality/value

Very limited literature dealt with the stability of channels under combined loading. A new numerical algorithm is provided to practitioners to utilize in the industry for analysis of channel sections under combined loading. Unlike finite element or finite strip methods, the channel is not discretized into subelements. Mathematical programming technique is used to find the buckling load. Parametric studies are then carried out to highlight influences of geometric interaction of the channel components and to provide useful guidance to the design of CFS channels.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 6
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 20 September 2021

Osama Bedair

This paper presents a novel concept for design of concrete support system for chemical reactors used in refineries and petrochemical plants. Graphical method is described that can…

Abstract

Purpose

This paper presents a novel concept for design of concrete support system for chemical reactors used in refineries and petrochemical plants. Graphical method is described that can be used to size the concrete base and piling system. Recommendations are also provided to optimize the parameters required for the design. The procedure is illustrated for design of two reactor models commonly used in gas recovery units.

Design/methodology/approach

Design space representation for the foundation system is described for chemical reactors with variable heights. The key points of the design graph are extracted from the numerical finite element models. The reactor load is idealized at discrete points to transfer the loads to the piles. Bilateral spring system is used to model the soil restrains.

Findings

The graphical approach is economical and provides the design engineer the flexibility to select the foundation parameters from wide range of options.

Practical implications

The concept presented in the paper can be utilized by engineers in the industry for design of chemical reactors. It must be noted that little guidelines are currently available in practice addressing the structural design aspects.

Originality/value

A novel concept is presented in this paper based on significant industrial design experience of reactor supports. Using the described method leads to significant cost savings in material quantity and engineering time.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 6
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 20 July 2021

Osama Bedair

Delays in projects execution due to improper structural design lead to substantial losses to the owners. Little guidelines are available in practice that deals with structural…

Abstract

Purpose

Delays in projects execution due to improper structural design lead to substantial losses to the owners. Little guidelines are available in practice that deals with structural design of Delayed Coker Units (DCUs). This work describes effective structural criteria for design of DCU used in hydrocarbon industry. Economical procedures are described for steel and concrete design. Design of pump houses supporting DCU is also described.

Design/methodology/approach

Numerical procedures are developed to model pipelines and mechanical equipment loadings. Soil restraints are simulated using horizontal and vertical springs along the pile embedded length. Concrete pile-caps are integrated with steel structure in the analysis model.

Findings

The proposed design approach is cost effective to use in practice. The paper offers economical footprint for design of DCUs that can be used for multiple projects.

Practical implications

The paper provides useful guidelines that can be utilized by engineers for design of coker heater and coker fractionation stacks, steel modules, coke pump house, deluge building, etc.

Originality/value

Currently, there are no guidelines in practice that deal with structural design of DCU. The present work bridges this gap and describes novel strategies that can be utilized for industrial projects.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 21 June 2013

Osama Bedair

The paper aims to review recent developments for analysis of deteriorating stiffened panels subjected to static and explosive forces.

Abstract

Purpose

The paper aims to review recent developments for analysis of deteriorating stiffened panels subjected to static and explosive forces.

Design/methodology/approach

The first part reviews numerical procedures developed for stiffened panels subjected to explosive forces. The structural idealization, the theoretical basis, and the merits of these methods are discussed. The second part reviews the probabilistic procedures developed for analysis of deteriorating stiffened panels. The third part reviews recent work developed in several finite element modelling philosophies for analysis of stiffened panels. The influence of various parameters affecting the structural performance, such as geometric and material imperfections, corrosion, residual stresses, etc. is discussed. The fourth part reviews hybrid procedures developed to provide approximate solutions for the designers. Numerical procedure is presented using combination of energy formulations and mathematical programming techniques to model the interaction between the box girder components.

Findings

Localized damage largely affects the performance of stiffened panels and must be accounted for in the design phase. Little emphasis was given in the published literature to developing simplified analytical models that can be used in practice to compute the residual strength of the stiffened panels under these types of loadings. Furthermore, analytical expressions are required to compute the reduction in the stiffness induced due to the structural or material defects. These expressions must be dependent on the type of damage. It must be noted that some of this damages is localized in nature and must be accounted for by using specialized functions to assess the structural defect accurately. Research work is required in this direction.

Practical implications

The paper provides useful resource material for the engineers in practice regarding recent techniques developed to assess damaged stiffened panels subject to static and explosive loadings. The paper reviews work developed over the past 20 years that can be used as a baseline for future developments.

Originality/value

Very limited literature dealt with the ultimate strength of damaged stiffened structure under static and explosive forces. No guidelines are available in current design codes to assess the damage in predicting the strength of deteriorating stiffened panels.

Details

Multidiscipline Modeling in Materials and Structures, vol. 9 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 15 November 2011

Osama Bedair

The purpose of this paper is to investigate the structural interactions of stiffened box girders used in bridge construction and industrial facilities.

Abstract

Purpose

The purpose of this paper is to investigate the structural interactions of stiffened box girders used in bridge construction and industrial facilities.

Design/methodology/approach

Numerical procedure is presented using combination of energy formulations and mathematical programming techniques to model the interaction between the box girder components.

Findings

Interactive buckling is a critical issue that must be accounted for in the design of box girders. Ignoring the structural interaction may lead to failures and damages prior to the expected design life.

Practical implications

Industrial examples are presented showing the variation of the flange buckling stress for various stiffening configurations. Graphs are presented for several box sections to provide cost‐effective design space that can be effectively used in the industry to optimize the sections proportions.

Originality/value

Limited literature dealt with these aspects in the design of box girders. Current design equations available in codes of practice ignore the interaction between the stiffened box girder components. The paper highlights the influence of the flange/web proportions on the behavior of box sections subjected to various types of loadings. It is shown that behavior of the flange is largely affected by the restraints imposed by the webs.

Details

Multidiscipline Modeling in Materials and Structures, vol. 7 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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