Edward I . Adah | University of Calabar, Calabar, Nigeria. (original) (raw)

Papers by Edward I . Adah

Journal of Inventive Engineering and Technology, 2025

The failure of engineering structures can have catastrophic consequences, leading to significant ... more The failure of engineering structures can have catastrophic consequences, leading to significant economic losses-both material and financial-and, in some cases, loss of human lives. Such failures often occur due to inadequate determination of structural loads or when materials exceed their yield strength, causing excessive deformation. This study revisits von Mises' theory and presents a newly formulated general applied stress mathematical model. Polynomial displacement shape profiles were employed to evaluate n-values for different plate types, leading to the derivation of n-value equations. Additionally, new general applied stress equations, Stress Factor (Fss), equations for shear strain energy theory for various boundary conditions, and allowable stress equations were developed. Validation of the newly formulated equations revealed that the applied stress values exceeded the yield stress of structural steel for plates with one free edge. To mitigate potential failure, a safety factor of 1.15 was introduced for the plate types considered which reduces the applied stress of 281N/mm2 to allowable stress of 244N/mm2 below the material yield stress of 250N/mm2. The results obtained align with findings from existing literature, confirming the reliability of the developed equations. As such, the new equations provide an effective means of predicting the allowable stress of plane materials based on the maximum shear strain energy theory.

Civil Engineering Journal

The objective of this research is to predict how strip footings behave when rested on an undraine... more The objective of this research is to predict how strip footings behave when rested on an undrained clay layer enhanced using a top replacement layer with and without a geo-grid. The study was conducted in several stages, including collecting load-settlement curves from "Finite Element Method" (FEM) models with different clay strengths, replacement thicknesses, and axial stiffnesses of the geo-grid. These curves were then idealized using a hyperbolic model, and the idealized hyperbolic parameters were predicted using three different AI techniques. According to the numerical results, the ultimate bearing pressure of pure clay models was found to be five times the undrained strength of the clay. These findings align with most established empirical bearing capacity formulas for undrained clays. The results also suggest that the initial modulus of the subgrade reaction is solely influenced by replacement thickness. Additionally, the enhancement in subgrade reaction due to the r...

Journal of Mechanical Engineering

At the moment, the analyses of postbuckling behavior of thin rectangular plates of constant thick... more At the moment, the analyses of postbuckling behavior of thin rectangular plates of constant thickness are generally based on von Karman’s large deflection equations which make use of stress functions and trigonometric variables. These equations are coupled, nonlinear partial differential equations of fourth order each. Getting a closed-form solution of these equations is near impossible and tedious. The present work presents a simplified closed-form general equation using a variational approach for large deflection analysis. The approach adopted here is devoid of Airy’s stress functions. A new strain-displacement equation is formulated, and the total potential energy equation is minimized. The resulting compatibility equation was solved to obtain the general governing stability equation under large deflection. This governing equation was applied to a plate simply supported all-around using polynomial displacement function and numerical results were obtained. To validate the numerica...

Matlab Based Buckling Analysis of Thin Rectangular Flat Plates

The Journal of Engineering Research, 2019

One of the major problems of rectangular platebuckling under in-plane load is the rigorous approa... more One of the major problems of rectangular platebuckling under in-plane load is the rigorous approach use in its analysis. In this study, the problem of buckling was addressed by developing a Matlab based computer program for ease of analysis of rectangular plates for critical buckling load, which is needed for safe design.The plates were assumed to be loaded axially along the x-axis, and polynomial shape functions used in Ritz energy equation to formulate a general solutionwhich is computer user-friendly. The critical buckling load coefficients’ 'n' values obtained from this program were compared with thoseavailablein scholarly literaturesso as to demonstrate theirvalidity. These values were found to be very close to existing values in literature. It therefore implies that, this general computer program for buckling analysis of rectangular plates is a better and quicker means of obtaining the critical buckling load of rectangular thin isotropic plates.

Development of Polynomial Based Programfor Pure Bending Analysis of SSSS Rectangular Thin Isotropic Plate

The study is aimed at developing a Polynomial Based Program for analysis of SSSS rectangular plat... more The study is aimed at developing a Polynomial Based Program for analysis of SSSS rectangular plate using polynomial shape functions derived for SSSS Plate. This shape functions were substituted in the Total Potential Energy functional equation derived based on Ritz energy equation to obtain expression for the coefficient of amplitude of deflection which was used to compute other parameters. The program is written based on the derived expressions using Matlab programming language in which provision is made for input by user. The values of coefficients of deflection, moments and shear forceswere obtained from running the program, and were compared with those of earlier studies. The percentage difference for aspect ratios of 1.0, 1.2,1.5, 1.6 and 2.0for amplitude of deflection and maximum deflection at the center of the plate were all 0.00% and 0.00% respectively.Those of bending moments and shear force coefficients were all less than 0.007% for both x-& ydirections. These indicate tha...

Structural Characteristics of Sawdust-Sand-Cement Composite

This research presents the structural characteristics of sawdust-sand-cement composite. It addres... more This research presents the structural characteristics of sawdust-sand-cement composite. It addresses the problem of absence of structural characteristics of sawdust-sand-cement composite which is a concrete mixture of sawdust, cement and sand. The materials used in the laboratory experiments include: Ordinary Portland Cement, river sand, sawdust, and water. The physical and mechanical characterization tests were performed on the aggregate and sawdust used in this experimental work of which Sawdust gave values of 733.92kg/m3, 0.35, 14%, 1.0, 2.8 for average bulk density, average specific gravity, water absorption, coefficient of curvature (Cc) and uniformity (Cu) respectively; sand gave values of 1564kg/m3, 2.65, 1.53, 2.0 for average bulk density, specific gravity, coefficient of curvature (Cc) and uniformity (Cu) respectively. Manual mixing operation was adopted and all sawdust-sand-cement composite ingredients where batched by weight. A total of nine (9) cubes of size 150mm x 150m...

Simple and Exact Approach to Post Buckling Analysis of Rectangular Plate

International Journal of Civil Engineering

This paper presents a new, simple and exact approach to post-buckling analysis of thin rectangula... more This paper presents a new, simple and exact approach to post-buckling analysis of thin rectangular plates. In the study, the Airy's stress functions are not incorporated as the middle surface axial displacement equations are determined as direct functions of middle surface deflection. With this the bending and membrane stresses and strains, which are direct functions of middle surface deflection are obtained. These stresses and strains are used to obtain the total potential energy functional. The minimization of the total potential energy gives the governing equation and compatibility equation for rectangular thin plates buckling with large deflection. The compatibility equations and the governing equation are solved to obtain the deflection function for the problem. Direct variation is applied on the total potential energy function to get the formula to calculate the buckling loads. A numeric analysis is performed for a plate with all the four edges simply supported (SSS plate). It is observed that when deflection to thickness ratio (w/t) is zero the buckling load obtained coincides with the critical buckling from small deflection (linear) analysis. Another observation is that the values of buckling load for given values of w/t obtained in the present study do not vary significant with those obtained by Samuel Levy. The recorded average percentage difference is 12.65%. It is also observed that the maximum w/t to be considered when small deflection analysis is to be used is 0.225. When w/t is more than 0.225, using small deflection analysis will give erroneous results. Thus, large deflection analysis is recommended when w/t is above 0.25. We conclude and recommend that this new equation for analysis of thin plates is a better alternative to the popular von Karman equation. Key words: Post-buckling buckling load, membrane strains, total potential energy, minimization, direct variation

Analysis of Continuous Plate Using Polynomial Displacement Functions Based on Beam Analogy

UMUDIKE JOURNAL OF ENGINEERING AND TECHNOLOGY

This study presents a new approach aimed at analyzing continuous plate based on beam analogy usin... more This study presents a new approach aimed at analyzing continuous plate based on beam analogy using polynomial displacement functions to obtain fixed edge moments, support moments, and span moments. A continuous plate along x-direction was divided into four (4) panels making up 4-spans of single panel plates based on boundary conditions. The external edges are assumed to be simply supported while the internal supports or edges of each panel are assumed fixed. The moments of the fixed edges are calculated for each panel using appropriate boundary conditions which formed the fixed edge moments (FEMs). After which a strip section is taken and analyzed based on beam analogy using the stiffness method to obtain the support and span moments of the plate. The support moments obtained showed a good distribution of the FEMs with a percentage difference of 3.57. This work further suggests expressions based on the results obtained to simplify continuous plate analysis. The approach presents here is easy to comprehend and less tedious compared with those in literature. Therefore, the conclusion that the polynomial displacement functions are adequate for predicting the moments of a continuous plate, and that, beam analogy is a simpler approach of analyzing continuous plate in one direction.

Global Journal of Pure and Applied Sciences, 2021

The present study presents a computer approach based on polynomial shape functions application fo... more The present study presents a computer approach based on polynomial shape functions application for analysis of continuous plate in one direction using Matlab. A 4-span continuous plate in the x-direction comprises of boundary conditions SSSC, SCSC, SCSC and SCSS single panels’ plate was analyzed. It was assumed that, the external edges were simply supported while the internal edges of each panel were clamped. The bending moments of the clamped edges were calculated for each panel using appropriate boundary conditions which formed the fixed end moments (FEMs). Stiffness method was used based on beam analogy to analyze the continuous plate. Matlab codes were applied to develop a computer program for this analysis. To validate the results of this present study, the values of the moments obtained were compared with those of earlier studies using manual method. The percentage difference for fixed end moments were all 0.00% and that of support moments had the maximum value of 0.016%. Thus...

ISOR Journal of Mechanical and Civil Engineering, 2021

Background: Basalt is a dark coloured, hard, dense, fine grained basic volcanic extrusive rock. I... more Background: Basalt is a dark coloured, hard, dense, fine grained basic volcanic extrusive rock. It is a very important rock widely spread across Ikon in Cross River State of Nigeria and the globe. It is extensively used as engineering materials such as basalt reinforcing fibre, as coarse aggregates for cement and asphaltic concrete mix, rock fill for dams and break waters in sea port construction, material for rail road ballast and highway base course. Materials and Methods: Basalt coarse aggregate samples were collected from the site and examined in the laboratory using X-ray diffraction method. Results: The samples were found to contain a major percentage of Silicon oxide followed by Aluminium oxide and other trace minerals such as Antimony oxide, Strontium oxide and Lead oxide. The results show that the mineralogical composition of Basalt in Ikom are suitable for use as coarse aggregates in the production of concrete for structural elements.

Global Journal of Pure and Applied Science, 2021

The present study presents a computer approach based on polynomial shape functions application fo... more The present study presents a computer approach based on polynomial shape functions application for analysis of continuous plate in one direction using Matlab. A 4-span continuous plate in the x-direction comprises of boundary conditions SSSC, SCSC, SCSC and SCSS single panels' plate was analyzed. It was assumed that, the external edges were simply supported while the internal edges of each panel were clamped. The bending moments of the clamped edges were calculated for each panel using appropriate boundary conditions which formed the fixed end moments (FEMs). Stiffness method was used based on beam analogy to analyze the continuous plate. Matlab codes were applied to develop a computer program for this analysis. To validate the results of this present study, the values of the moments obtained were compared with those of earlier studies using manual method. The percentage difference for fixed end moments were all 0.00% and that of support moments had the maximum value of 0.016%. Thus, it was concluded that the present study program based on Matlab is adequate and a faster approach for a 4span continuous plate in one direction analysis.

Journal of Civil Engineering, Science and Technology, 2021

The major assumption of the analysis of plates with large deflection is that the middle surface d... more The major assumption of the analysis of plates with large deflection is that the middle surface displacements are not zeros. The determination of the middle surface displacements, u0 and v0 along x-and y-axes respectively is the major challenge encountered in large deflection analysis of plate. Getting a closed-form solution to the long standing von Karman large deflection equations derived in 1910 have proven difficult over the years. The present work is aimed at deriving a new general linear and nonlinear free vibration equation for the analysis of thin rectangular plates. An elastic analysis approach is used. The new nonlinear strain displacement equations were substituted into the total potential energy functional equation of free vibration. This equation is minimized to obtain a new general equation for analyzing linear and nonlinear resonating frequencies of rectangular plates. This approach eliminates the use of Airy's stress functions and the difficulties of solving von Karman's large deflection equations. A case study of a plate simply supported all-round (SSSS) is used to demonstrate the applicability of this equation. Both trigonometric and polynomial displacement shape functions were used to obtained specific equations for the SSSS plate. The numerical results for the coefficient of linear and nonlinear resonating frequencies obtained for these boundary conditions were 19.739 and 19.748 for trigonometric and polynomial displacement functions respectively. These values indicated a maximum percentage difference of 0.051% with those in the literature. It is observed that the resonating frequency increases as the ratio of out-of-plane displacement to the thickness of plate (w/t) increases. The conclusion is that this new approach is simple and the derived equation is adequate for predicting the linear and nonlinear resonating frequencies of a thin rectangular plate for various boundary conditions.

Umudike Journal of Engineering and Technology, 2020

IOSR Journal of Mechanical and Civil Engineering, 2021

The use of trigonometric shape functions in analysis of continuous plates in two directions by ea... more The use of trigonometric shape functions in analysis of continuous plates in two directions by earlier researchers have been with a lot of difficulties of complex and cumbersome equations. In this study, polynomial displacement functions are used toanalyze a two-way continuous plate. A continuous plate spanning in both x and y-directionsis divided into twelve (12) panels, four(4) panels each along the x-direction and three(3) panels each along the y-direction. The external edges are assumed simply supported while the internal edges of each panel are assumed clamped. Edge moments of the clamped edges are calculated for each panel using appropriate boundary conditions which formed the fixed end moments(FEMs). Beam analogy is use to analyze the continuous plate using stiffness method in both directions to obtain the support and span moments. The support moments obtainedare comparedwith the fixed end moment. These showed a good distribution of the FEMs with percentage difference of 6.1% maximum in both directions. Simple equations are proposed based on the obtained result to quicken the analysis and design. Therefore, we conclude that analysis of continuous plate in two directions is adequate and easier with the use of polynomial displacement shape functions.

SSRG International Journal of Civil Engineering, 2020

Key words: Post-buckling buckling load, membrane strains, total potential energy, minimization, direct variation

IOSR Journal of Mechanical and Civil Engineering, 2019

This research work is aimed at modifying the postbuckling equation derived by Iyengar based on cl... more This research work is aimed at modifying the postbuckling equation derived by Iyengar based on classical approach for a plate simply supported alround (SSSS). The equation in its present form lacks numerical application to postbuckling analysis of SSSS rectangular thin plate because of the difficulties of determining the variables ‘EI’ which is the slope of the stress-strain curve at the inelastic range and ‘A’ the amplitude of deflection. In order to circumvent this, mathematical manipulation has been carried out on the equation to make the equation easily usable. The new expressions were applied using polynomial shape function to determine the postbuckling load of SSSS plate and the numerical factor β. From the results gotten, comparison was made with those in literature and it was found that the values agreed very closely with those compared with and the numerical factor ‘β’ was found to be 0.025. Therefore, the conclusion that the new expressions in this work are adequate and an easy expression for postbuckling analysis of SSSS rectangular plates.

The International Journal of Engineering and Science, 2016

The paper is aim at the development of a computer program for free vibration analysis of an all-r... more The paper is aim at the development of a computer program for free vibration analysis of an all-round clamped (i.eCCCC) rectangular thin isotropic plate. Polynomial-based shape function for a CCCC plate, was used in Ritz energy equation to formulate an equation in term of a non-dimensional parameter 'k' for calculating the fundamental natural frequency of the plate. Computer program based on the formulated equation was develop in Matlab language for calculating fundamental natural frequency of a CCCC rectangular thin isotropic plate subjected to free vibration. To validate the values of the fundamental natural frequency obtained from the program, comparison was made between the values obtained and those available in relevant existing literatures. And the average percentage difference was 0.079% which is acceptable. Hence, it can be deduce that the computer program can be adopted as a better and faster alternative to the former rigorous approaches for obtaining the fundamental natural frequency of CCCC plate.

International Journal of Science, Engineering and Technology Research, 2016

American Journal of Engineering Research, 2019

The International Journal of Science and Technoledge, 2016

Two thin rectangular plates, one simply supported on all sides (SSSS), and the other plate simply... more Two thin rectangular plates, one simply supported on all sides (SSSS), and the other plate simply supported and fixed on
alternate opposite sides(CSCS), were analyzed for buckling or stability. Polynomial series were used to formulate shape
functions for plates loaded axially along the x- axis. The shape functions were used in Ritz energy equation to obtain the
critical buckling loads 'Nx' for the plates studied. Computer programs based on the formulated critical buckling load
equation were developed in MATLAB language for easier and faster stability analysis of aforementioned plates. In order to
validate the results obtained from the computer program, comparison was made with other results from literature. For
simply supported plate with aspect ratios of 1.0, 1.2, 1.5, 1.6 and 2.0, the maximum percentage difference is 0.02%. And for
the plate with alternate opposite simply supported and fixed edge, the maximum percentage difference from the computed
values of 'n' and those in literature is -0.19%. In both cases, the percentage differences are less than 1% which is consider
very insignificant. Therefore, the developed MATLAB programs can be used to analyze accurately the critical buckling load
of SSSS and CSCS plates.

Journal of Inventive Engineering and Technology, 2025

Civil Engineering Journal

Journal of Mechanical Engineering

Matlab Based Buckling Analysis of Thin Rectangular Flat Plates

The Journal of Engineering Research, 2019

Development of Polynomial Based Programfor Pure Bending Analysis of SSSS Rectangular Thin Isotropic Plate

Structural Characteristics of Sawdust-Sand-Cement Composite

Simple and Exact Approach to Post Buckling Analysis of Rectangular Plate

International Journal of Civil Engineering

Analysis of Continuous Plate Using Polynomial Displacement Functions Based on Beam Analogy

UMUDIKE JOURNAL OF ENGINEERING AND TECHNOLOGY

Global Journal of Pure and Applied Sciences, 2021

ISOR Journal of Mechanical and Civil Engineering, 2021

Global Journal of Pure and Applied Science, 2021

The present study presents a computer approach based on polynomial shape functions application fo... more The present study presents a computer approach based on polynomial shape functions application for analysis of continuous plate in one direction using Matlab. A 4-span continuous plate in the x-direction comprises of boundary conditions SSSC, SCSC, SCSC and SCSS single panels' plate was analyzed. It was assumed that, the external edges were simply supported while the internal edges of each panel were clamped. The bending moments of the clamped edges were calculated for each panel using appropriate boundary conditions which formed the fixed end moments (FEMs). Stiffness method was used based on beam analogy to analyze the continuous plate. Matlab codes were applied to develop a computer program for this analysis. To validate the results of this present study, the values of the moments obtained were compared with those of earlier studies using manual method. The percentage difference for fixed end moments were all 0.00% and that of support moments had the maximum value of 0.016%. Thus, it was concluded that the present study program based on Matlab is adequate and a faster approach for a 4span continuous plate in one direction analysis.

Journal of Civil Engineering, Science and Technology, 2021

Umudike Journal of Engineering and Technology, 2020

IOSR Journal of Mechanical and Civil Engineering, 2021

SSRG International Journal of Civil Engineering, 2020

Key words: Post-buckling buckling load, membrane strains, total potential energy, minimization, direct variation

IOSR Journal of Mechanical and Civil Engineering, 2019

The International Journal of Engineering and Science, 2016

International Journal of Science, Engineering and Technology Research, 2016

American Journal of Engineering Research, 2019

The International Journal of Science and Technoledge, 2016