Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3460 https://internationalpubls.com Analysis of Three-Dimensional Non-Homogeneous Fractional order Thermoelastic Problem of Thick Rectangular Plate with Internal Heat Generation Yogesh U. Naner𝟏, Satish G. Khavale𝟐, Kishor. R. GaikwadπŸ‘ 1Department of Mathematics, Shri Vitthal Rukhmini Arts, Commerce and Science College, Sawana, Yavatmal, Maharashtra, India-445205. 2Department of Mathematics, Statistics and Computer Science, Chetana’s H. S. College of Commerce and Economics, SMT. K. C. College of Art, Bandra (East), Mumbai, Maharashtra, India - 400051. 3Post Graduate Department of Mathematics, N. E. S., Science College, Nanded, Maharashtra, India - 431605. Email- ynaner@gmail.com, khavalesatish8@gmail.com , drkr.gaikwad@yahoo.in , satish.khavale@chetanacollege.in Article History: Received: 19-08-2025 Revised: 24-09-2025 Accepted: 15-10-2025 Abstract: This paper investigates the thermal behaviour of a three-dimensional thick rectangular plate governed by a fractional-order derivative. The plate, occupying the region 𝐷 = {(π‘₯, 𝑦, 𝑧) ∈ 𝑅3: 0 ≀ π‘₯ ≀ π‘Ž, 0 ≀ 𝑦 ≀ 𝑏, 0 ≀ 𝑧 ≀ 𝑐}, is initially at an arbitrary temperature distribution 𝑓(π‘₯, 𝑦, 𝑧). For 𝑑 > 0, the plate experiences internal heat generation represented by 𝑔(π‘₯, 𝑦, 𝑧, 𝑑) Btu/hr ft3, while all boundary surfaces are maintained at zero temperature. The governing model is formulated using the Caputo fractional derivative, and analytical solutions for temperature, displacement, and thermal stresses are derived through the integral transform technique. Numerical simulations are carried out using PTC Mathcad software, and the results are illustrated graphically. The study highlights the influence of the fractional-order parameter on heat conduction, displacement, and stress distribution, demonstrating the effectiveness of fractional-order thermoelastic models in capturing nonlocal thermal effects. Introduction: The study of thermoelastic behaviour in solid materials has gained significant importance due to its wide applications in aerospace, mechanical, and civil engineering. Classical thermoelastic theories often assume instantaneous heat propagation, which contradicts physical reality. To overcome this limitation, fractional- order thermoelasticity has been introduced as an effective approach to model heat conduction with memory and nonlocal effects. In this paper, a three-dimensional non- homogeneous thick rectangular plate with internal heat generation is analysed using the Caputo fractional derivative. The objective is to investigate how the fractional-order parameter (Ξ±) influences temperature, displacement, and stress distributions. The proposed model provides a more generalized framework that includes both the classical and wave-type heat conduction as special cases, thus offering a realistic representation of transient thermal behaviour in thick plates. Objectives: 1. To investigate the thermal behaviour of a three-dimensional thick rectangular plate subjected to internal heat generation. 2. To analyse the effect of the fractional-order parameter (Ξ±) on temperature, displacement, and thermal stresses. 3. To demonstrate the usefulness of fractional-order thermoelastic models in capturing nonlocal and memory effects in heat conduction. Methods: The governing equations are derived using the Caputo fractional derivative for time-fractional heat conduction. Integral transform techniques are employed to obtain analytical solutions for temperature, displacement, and stress fields. Mittag- mailto:ynaner@gmail.com mailto:khavalesatish8@gmail.com mailto:drkr.gaikwad@yahoo.in mailto:satish.khavale@chetanacollege.in Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3461 https://internationalpubls.com Leffler functions are used in the solutions to describe the fractional behaviour. Numerical simulations are performed in PTC Mathcad Prime for a thick rectangular plate using physical constants. Results: The temperature distribution decreases with increasing fractional order Ξ± and is maximum at the centre of the plate. Displacement components show symmetrical behaviour, increasing from the edges and vanishing at the centre. Stress components are compressive, peaking at the middle of the plate and zero at the edges. The fractional order parameter Ξ± significantly affects heat transfer. Graphs demonstrate clear variation between classical (Ξ± = 1) and fractional-order (Ξ± β‰  1) thermoelastic behaviour. Conclusions: For Ξ± = 1, the model reduces to the classical heat diffusion equation, while Ξ± = 2 corresponds to the wave equation. The fractional order 0 < Ξ± < 1, Ξ± = 1, and 1 < Ξ± < 2 represent weak, normal, and strong conductivity, respectively. Stress distributions are tensile/compressive and follow normal curves in all directions, directly proportional to Ξ±. The fractional order Ξ± governs nonlocal heat transfer, influencing both response time and temperature overshoot. The model effectively describes transient thermoelastic behavior in thick plates and can be applied to other nonhomogeneous materials. Keywords: Thermal Behavior, Internal Heat Source, Caputo Fractional Derivative, Thick Rectangular Plate, Mittag-Leffler Functions. 1. Introduction Biot [1] formulated the theory of coupled thermoelasticity to eliminate the paradox inherent in the classical uncoupled theory that elastic changes have no effect on the temperature. The heat equations for both theories are of the diffusion type predicting infinite speeds of propagation for heat waves contrary to physical observations. The generalised thermoelastic problem of a thick plate under axi- symmetric heat supply was resolved by Sherief and Hamza [2]. The generalised dynamical theory of thermoelasticity with one relaxation period, for the isotropic body, was developed by Lord and Shulman [3]. In their study of the theoretical analysis of a rectangular plate in a compressive stress field and associated thermal stresses was resolved by Tanigawa and Komatsubara [4]. The solution to the plane thermoelasticity problem for a rectangular domain is discussed in Vihak et al., [5]. A laminated rectangular plate subjected to a thermal shock was the focus of an investigation by Adam and Best [6]. Tanigawa et al. [7 8]. investigate the thermal analysis of thermal buckling caused by uniform heat supply in an orthotropic nonhomogeneous rectangular plate. The transient thermoelastic deformations of a thick functionally graded plate were investigated by Qian and Batra [9]. The thermal behaviour of thermoelastic thick plates under lateral loads was presented by Sharma et. al. [10]. Based on the equation of heat conduction in 1D and 2D with a time-fractional derivative and related thermal stresses, Povstenko [11] resolved a few thermoelastic issues. Some contribution of thermoelastic problems and fractional order thermoelastic problems have been discussed in [12-34]. 2. Preliminaries In this section we give some definitions, notations and facts that we need in this article. β€’ The Riemann-Liouville Fractional Differential Operator The definition of the Riemann-Liouville fractional differential operator given by [37] Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3462 https://internationalpubls.com Suppose that 𝛼 > 0, t > a, 𝛼, a, t ∈ R. Then 𝐷𝛼𝑓(𝑑) = { 1 𝛀(𝑛 βˆ’ 𝛼) 𝑑𝑛 𝑑𝑑𝑛 ∫ 𝑓(𝜏) (𝑑 βˆ’ 𝜏)𝛼+1βˆ’π‘› π‘‘πœ 𝑑 0 , 𝑛 βˆ’ 1 < 𝛼 < 𝑛 ∈ 𝑁 𝑑𝑛𝑓(𝑑) 𝑑𝑑𝑛 , 𝛼 = 𝑛 ∈ 𝑁 (2.1) is called the Riemann-Liouville fractional derivative or the Riemann-Liouville fractional differential operator of order 𝛼. β€’ The Caputo Fractional Differential Operator The definition of the Caputo fractional differential operator given by [37] Suppose that 𝛼 > 0, t > a, 𝛼, a, t ∈ R. Then 𝐷𝛼𝑓(𝑑) = { 1 𝛀(𝑛 βˆ’ 𝛼) 𝑑𝑛 𝑑𝑑𝑛 ∫ 𝑓(𝑛)(𝜏) (𝑑 βˆ’ 𝜏)𝛼+1βˆ’π‘› π‘‘πœ 𝑑 0 , 𝑛 βˆ’ 1 < 𝛼 < 𝑛 ∈ 𝑁 𝑑𝑛𝑓(𝑑) 𝑑𝑑𝑛 , 𝛼 = 𝑛 ∈ 𝑁 (2.2) is called the Caputo fractional derivative or the Caputo fractional differential operator of order 𝛼. β€’ The Mittag-Leffler Function The Mittag-Leffler function is a generalization of the exponential function, first introduced as a one- parameter function by the series 𝐸𝛼(𝑧) = βˆ‘ π‘§π‘˜ 𝛀(π›Όπ‘˜ + 1) ∞ π‘˜=0 , 𝛼 > 0, β€„π›Όβ€„πœ–β€„π‘…, 𝑧  ∈  𝐢 (2.3) Later, the two-parameter generalization Mittag-Leffler function as: 𝐸𝛼,𝛽(𝑧) =βˆ‘ π‘§π‘˜ 𝛀(π›Όπ‘˜ + 𝛽) ∞ π‘˜=0 , 𝛼, 𝛽 > 0,  𝛼, 𝛽  ∈  𝑅, 𝑧  ∈  𝐢 (2.4) 3. Problem formulation Consider a thick rectangular plate with length π‘Ž, width 𝑏 and thickness 𝑐 occupying the space 𝐷 = {(π‘₯, 𝑦, 𝑧) ∈ 𝑅3: 0 ≀ π‘₯ ≀ π‘Ž, 0 ≀ 𝑦 ≀ 𝑏, 0 ≀ 𝑧 ≀ 𝑐}. Initially the rectangular plate is at arbitrary temperature 𝑓(π‘₯, 𝑦, 𝑧). For time 𝑑 > 0, heat is generated within the plate at a rate of 𝑔(π‘₯, 𝑦, 𝑧, 𝑑) Btu/hr ft3, while the remaining boundaries are kept at zero temperature. An equation of the Caputo type time fractional differential equation of order 𝛼 is used to create a mathematical model that consider a thick rectangular plate with internal heat generation. The temperature 𝑇(π‘₯, 𝑦, 𝑧, 𝑑) of the thick rectangular plate at time 𝑑 satisfying the time fractional heat conduction equation βˆ‚2𝑇 βˆ‚π‘₯2 + βˆ‚π‘‡ βˆ‚π‘¦2 + βˆ‚2𝑇 βˆ‚π‘§2 + 𝑔(π‘₯, 𝑦, 𝑧, 𝑑) π‘˜π‘‘ = 1 π‘˜ βˆ‚π›Όπ‘‡ βˆ‚π‘‘π›Ό , (3.1) where π‘˜π‘‘ and π‘˜ are thermal conductivity and thermal diffusivity of the material of the plate. with the boundary conditions, 𝑇 = 0,  at all boundary surfaces for 𝑑 > 0, (3.2) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3463 https://internationalpubls.com and initial conditions, 𝑇 = 𝑓(π‘₯, 𝑦, 𝑧),  at 𝑑 = 0, 0 < 𝛼 ≀ 1 , (3.3) βˆ‚π‘‡ βˆ‚π‘‘ = 0,  at 𝑑 = 0, 1 < 𝛼 ≀ 2 (3.4) Fig. 1. Geometrical representation of the plate. 4. Analysis Here the plate is assumed sufficiently thick and considered free from traction. Since the plate is in a plane stress state without bending. Airy stress function method is applicable to the analytical development of the thermoelastic field. Airy stress function π‘ˆ(π‘₯, 𝑦, 𝑧, 𝑑) which satisfy the following relation ( βˆ‚2 βˆ‚π‘₯2 + βˆ‚ βˆ‚π‘¦2 + βˆ‚2 βˆ‚π‘§2 ) 2 π‘ˆ = βˆ’πœ†πΈ ( βˆ‚2 βˆ‚π‘₯2 + βˆ‚ βˆ‚π‘¦2 + βˆ‚2 βˆ‚π‘§2 )𝑇 (4.1) where πœ† and 𝐸 are linear coefficient of the thermal expansion, Youngs modulus elasticity of the material of the plate. The displacement components 𝑒π‘₯, 𝑒𝑦 and 𝑒𝑧 in the 𝑋, π‘Œ and 𝑍 direction are represented in the integral form as 𝑒π‘₯ = ∫[ 1 𝐸 ( βˆ‚2π‘ˆ βˆ‚π‘¦2 + βˆ‚2π‘ˆ βˆ‚π‘§2 βˆ’ 𝜈 βˆ‚2π‘ˆ βˆ‚π‘₯2 ) + πœ†π‘‡] 𝑑π‘₯ (4.2) 𝑒𝑦 = ∫[ 1 𝐸 ( βˆ‚2π‘ˆ βˆ‚π‘₯2 + βˆ‚2π‘ˆ βˆ‚π‘§2 βˆ’ 𝜈 βˆ‚2π‘ˆ βˆ‚π‘¦2 ) + πœ†π‘‡] 𝑑𝑦 (4.3) 𝑒𝑧 = ∫[ 1 𝐸 ( βˆ‚2π‘ˆ βˆ‚π‘₯2 + βˆ‚2π‘ˆ βˆ‚π‘¦2 βˆ’ 𝜈 βˆ‚2π‘ˆ βˆ‚π‘§2 ) + πœ†π‘‡] 𝑑𝑧 (4.4) where 𝜈 is the poissons ratio of the material of the plate. The stress components are: Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3464 https://internationalpubls.com 𝜎π‘₯π‘₯ = ( βˆ‚2π‘ˆ βˆ‚π‘¦2 + βˆ‚2π‘ˆ βˆ‚π‘§2 ) (4.5) πœŽπ‘¦π‘¦ = ( βˆ‚2π‘ˆ βˆ‚π‘₯2 + βˆ‚2π‘ˆ βˆ‚π‘§2 ) (4.6) πœŽπ‘§π‘§ = ( βˆ‚2π‘ˆ βˆ‚π‘₯2 + βˆ‚2π‘ˆ βˆ‚π‘¦2 ) (4.7) Equations [3.1] to [4.7] constitute the mathematical formulation of the problem under consideration. 5. Determination of Temperature Field To obtain the expression for temperature function 𝑇(π‘₯, 𝑦, 𝑧, 𝑑); we introduce the β€˜β€˜triple integral transform’’and its corresponding β€˜triple-inversion formula’ as defined in [35] respectively as 𝑇(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑) = ∫ ∫ ∫ 𝐾 𝑐 𝑧′=0 𝑏 𝑦′=0 π‘Ž π‘₯β€²=0 (π›½π‘š, π‘₯ β€²). 𝐾(πœˆπ‘›, 𝑦 β€²). 𝐾(πœ‚π‘, 𝑧 β€²) (5.1) Γ— 𝑇(π‘₯β€², 𝑦′, 𝑧′, 𝑑)𝑑π‘₯′𝑑𝑦′𝑑𝑧′ 𝑇(π‘₯, 𝑦, 𝑧, 𝑑) = βˆ‘βˆ‘βˆ‘πΎ ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘š, π‘₯). 𝐾(πœˆπ‘›, 𝑦).𝐾(πœ‚π‘, 𝑧)𝑇(π›½π‘š, πœˆπ‘›, πœ‚π‘ , 𝑑) (5.2) where the kernels 𝐾(π›½π‘š, π‘₯) = √ 2 π‘Ž sin(π›½π‘šπ‘₯) (5.3) 𝐾(πœˆπ‘›, 𝑦) = √ 2 𝑏 sin(πœˆπ‘›π‘¦) (5.4) 𝐾(πœ‚π‘, 𝑧) = √ 2 𝑐 sin(πœ‚π‘π‘§) (5.5) and eigenvalues are π›½π‘š is π‘šπ‘‘β„Ž root of transcendental equation sin(π›½π‘š . π‘Ž) = 0 i.e. π›½π‘š = π‘šπœ‹ π‘Ž ,β€β€π‘š = 1,2,3,… (5.6) πœˆπ‘› is π‘›π‘‘β„Ž root of transcendental equation sin(πœˆπ‘›. 𝑏) = 0 i.e. πœˆπ‘› = π‘›πœ‹ 𝑏 ,  𝑛 = 1,2,3,… (5.7) πœ‚π‘ is π‘π‘‘β„Ž root of transcendental equation sin(πœ‚π‘. 𝑐) = 0 Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3465 https://internationalpubls.com i.e. πœ‚π‘ = π‘πœ‹ 𝑐 ,  𝑝 = 1,2,3, … (5.7) On applying triple-integral transform defined in equation [5.1] to equations [3.1]–[3.4] and then using their inversions defined in equation [4.2], one obtains the expressions of the temperature as: 𝑇(π‘₯, 𝑦, 𝑧, 𝑑) = βˆ‘βˆ‘βˆ‘πΎ ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘š, π‘₯). 𝐾(πœˆπ‘›, 𝑦).𝐾(πœ‚π‘, 𝑧) 1 π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š , πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (5.9) where 𝐸𝛼,𝛼(. ) - two-parameter Mittag-Leffler function, 𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) = ∫ ∫ ∫ sin 𝑐 𝑧′=0 𝑏 𝑦′=0 π‘Ž π‘₯β€²=0 (π›½π‘šπ‘₯ β€²)sin(πœˆπ‘›π‘¦ β€²)sin(πœ‚π‘π‘§ β€²)𝑓(π‘₯β€², 𝑦′, 𝑧′)𝑑π‘₯′𝑑𝑦′𝑑𝑧′ 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑 β€²) = ∫ ∫ ∫ sin 𝑐 𝑧′=0 𝑏 𝑦′=0 π‘Ž π‘₯β€²=0 (π›½π‘šπ‘₯ β€²)sin(πœˆπ‘›π‘¦ β€²)sin(πœ‚π‘π‘§ β€²)𝑔(π‘₯β€², 𝑦′, 𝑧′, 𝑑′)𝑑π‘₯′𝑑𝑦′𝑑𝑧′ 6. Distributions of Displacement and Stresses Using equation [5.9] in [4.1], one obtains π‘ˆ = 8𝐸 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)sin(πœˆπ‘›π‘¦)sin(πœ‚π‘π‘§) 1 π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘ , 𝑑 β€²)] (6.1) Now using equations [5.9] and [6.1] in equations [4.2] to [4.4], one obtains the expressions for displacement as 𝑒π‘₯ = βˆ’8 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘( cos(π›½π‘šπ‘₯) π›½π‘š ) ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 sin(πœˆπ‘›π‘¦)sin(πœ‚π‘π‘§) [ (𝜈 βˆ’ 1)π›½π‘š 2 βˆ’ 2(πœˆπ‘› 2 + πœ‚π‘ 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 ] Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š , πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.2) 𝑒𝑦 = βˆ’8 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)( cos(πœˆπ‘›π‘¦) πœˆπ‘› )sin(πœ‚π‘π‘§) [ (𝜈 βˆ’ 1)πœˆπ‘› 2 βˆ’ 2(π›½π‘š 2 + πœ‚π‘ 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 ] Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ— ∫ [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.3) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3466 https://internationalpubls.com 𝑒𝑧 = βˆ’8 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)sin(πœˆπ‘›π‘¦)( cos(πœ‚π‘π‘§) πœ‚π‘ ) [ (𝜈 βˆ’ 1)πœ‚π‘ 2 βˆ’ 2(π›½π‘š 2 + πœˆπ‘› 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 ] Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š , πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.4) Now using equations [5.9] and [6.1] in equations [4.5] to [4.7], one obtains expressions for thermal stresses as 𝜎π‘₯π‘₯ = βˆ’8𝐸 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)sin(πœˆπ‘›π‘¦)sin(πœ‚π‘π‘§) (πœˆπ‘› 2 + πœ‚π‘ 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ— ∫ [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.5) πœŽπ‘¦π‘¦ = βˆ’8𝐸 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)sin(πœˆπ‘›π‘¦)sin(πœ‚π‘π‘§) (π›½π‘š 2 + πœ‚π‘ 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.6) πœŽπ‘§π‘§ = βˆ’8𝐸 π‘Žπ‘π‘ βˆ‘ βˆ‘βˆ‘sin ∞ 𝑝=0 ∞ 𝑛=0 ∞ π‘š=0 (π›½π‘šπ‘₯)sin(πœˆπ‘›π‘¦)sin(πœ‚π‘π‘§) (π›½π‘š 2 + πœˆπ‘› 2) π‘˜(π›½π‘š2 + πœˆπ‘›2 + πœ‚π‘2) 2 Γ— [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] [𝑓(π›½π‘š, πœˆπ‘›, πœ‚π‘) + π‘˜ π‘˜π‘‘ Γ—βˆ« [π‘‘π›Όβˆ’1𝐸𝛼,𝛼(βˆ’π‘˜(π›½π‘š 2 + πœˆπ‘› 2 + πœ‚π‘ 2)𝑑𝛼)] 𝑑 𝑑′=0 𝑔(π›½π‘š, πœˆπ‘›, πœ‚π‘, 𝑑 β€²)] (6.7) 7. Numerical Calculations and Discussion Setting 𝑓(π‘₯, 𝑦, 𝑧) = 𝑒𝑑(π‘Ž βˆ’ π‘₯)(1 βˆ’ 𝑒π‘₯)(𝑏 βˆ’ 𝑦)(1 βˆ’ 𝑒𝑦)(𝑐 βˆ’ 𝑧)(1 βˆ’ 𝑒𝑧), 𝑔(π‘₯, 𝑦, 𝑧, 𝑑) = 𝑔𝑖𝛿(π‘₯ βˆ’ π‘₯1)𝛿(𝑦 βˆ’ 𝑦1)𝛿(𝑧 βˆ’ 𝑧1)𝛿(𝑑 βˆ’ 𝜏) where 𝛿 is the Derac-delta function and 𝑔(π‘₯, 𝑦, 𝑧, 𝑑) is an instantaneous line heat source situated at the center of the rectangular plates. Dimension Length of rectangular plate π‘Ž = 3 ft Breadth of rectangular plate 𝑏 = 2 ft Height of rectangular plate 𝑐 = 1 ft Central length of rectangular plate π‘₯1 =1.5 ft Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3467 https://internationalpubls.com Central breadth of rectangular plate 𝑦1 = 1 ft Central 1eight of rectangular plate 𝑧1 = 0.5 ft For the purpose of doing a numerical calculation for a thick rectangular plate, the material aluminium (Pure) was selected. PTC Mathcad Prime, a computational mathematical software, was used to create the numerical calculations and graphics. The aluminium (pure) material was chosen for purposes of numerical evaluations. The parameters of the problem are given in FPS units, as illustrated in Table 1. TABLE -1:- MATERIAL CONSTANT Physical constant Value Thermal diffusivity (k) 3.33 ft2/hr Thermal conductivity (π‘˜π‘‘) 117 Btu/(hr.ft.0F) Density (𝜌) 169 lb/ft3 Specific heat (𝑐𝑝) 0.208 Btu/(lb.0F) Coefficient of linear thermal expansion (π‘Žπ‘‘) 12.84Γ—10βˆ’6 1/F Poisson ratio (𝜈) 0.35 Lame’s constants (πœ‡) 26.67 Young’s modulus (𝐸) 70 GPa In this section, we analysed a fractional heat conduction problem for a thick rectangular plate. We have discussed the variation of temperature, displacement and thermal stresses for different values of fractional-order parameter 𝛼 = 0.5,1,1.5,2. The graphs are plotted for different fractional-order parameter 𝛼 = 0.5,1,1.5,2 at time 𝑑 = 1 hr. Figure 2 shows the temperature distribution for different values of fractional-order parameter 𝛼 = 0.5,1,1.5,2 in 𝑋-direction. It is observed that, the magnitude of the temperature increases with decrease the value of fractional-order parameter 𝛼 and it attains its peak at π‘₯ = 1.5. Also, it is zero at both edges (π‘₯ = 0 and π‘₯ = 3) of the rectangular plate along the 𝑋-direction and it shows the normal curve. Figures 3–5 show the displacement distribution functions 𝑒π‘₯, 𝑒𝑦 and 𝑒𝑧 in 𝑋, π‘Œ and 𝑍-directions for different values of 𝛼. It is clear that, the displacement functions increase from initial edge towards the extreme edge and it becomes zero at the middle part for different values of 𝛼. Figure 6-8 shows the stress distribution 𝜎π‘₯π‘₯, πœŽπ‘¦π‘¦ and πœŽπ‘§π‘§ for different values of 𝛼 in 𝑋, π‘Œ and 𝑍- direction respectively. We observe that, the magnitude of both the stresses is maximum at the middle part with increasing the value of fractional-order parameter 𝛼 and becomes zero at the initial and extreme edges in the 𝑋, π‘Œ and 𝑍-direction respectively. Also, the stress components 𝜎π‘₯π‘₯, πœŽπ‘¦π‘¦ and πœŽπ‘§π‘§ are compressive throughout the plate and shows the normal curve. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3468 https://internationalpubls.com Fig. 2. Temperature distribution for different values of 𝛼 in 𝑋-direction. Fig. 3. Displacement distribution 𝑒π‘₯ for different values of 𝛼 in 𝑋-direction. Fig. 4. Displacement distribution 𝑒𝑦 for different values of 𝛼 in π‘Œ-direction. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3469 https://internationalpubls.com Fig. 5. Displacement distribution 𝑒𝑧 for different values of 𝛼 in 𝑍-direction. Fig. 6. Stress distribution 𝜎π‘₯π‘₯ for different values of 𝛼 in 𝑋-direction. Fig. 7. Stress distribution πœŽπ‘¦π‘¦ for different values of 𝛼 in π‘Œ-direction. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3470 https://internationalpubls.com Fig. 8. Stress distribution πœŽπ‘§π‘§ for different values of 𝛼 in 𝑍-direction. 8. Conclusion In this article, we proposed the time-fractional heat conduction equation with zero initial conditions. Integral transform technique is adopted for computing the temperature of heat conduction equation. The results are obtained in the form of two-parameter Mittag-Leffler function. Figures 2-8 shows the behavior of temperature, displacement and thermal stresses along 𝑋, π‘Œ and 𝑍 directions for the different values of the fractional-order parameter 𝛼 = 0.5,1,1.5,2 and shows the variation between classical and fractional-order thermoelasticity. The following concluding remakes can be considered according to the results of the present study. 1. When 𝛼 = 1, all the graphical representation satisfied the heat diffusion equation, whereas 𝛼 = 2, gives the representation of wave equations. 2. It is observed that, for the different values of the fractional-order parameter 𝛼 in the 𝑋, π‘Œ and 𝑍 directions the effect temperature, displacement and thermal stresses represents the weak, normal and strong conductivity, within the range of 0 < 𝛼 < 1, 𝛼 = 1 and 1 < 𝛼 < 2 respectively. 3. The stress distribution functions 𝜎π‘₯π‘₯, πœŽπ‘¦π‘¦ and πœŽπ‘§π‘§ are tensile and they form normal curve along the 𝑋, π‘Œ and 𝑍 direction respectively. Also, they are directly proportional to the different values of 𝛼 in the 𝑋, π‘Œ and 𝑍 direction respectively. 4. Fractional order 𝛼 governs the non-local behavior of heat transfer process, and then alters the response time and overshooting occurrence of the temperature. Larger the parameter 𝛼, the slower the velocity of heat waves-like. Its effect is limited to short times and disappears for long time. Refrences [1] M. A. Biot., β€œThermoelasticity and irreversible thermodynamics”, J. Appl. Phys, vol. 27, pp. 240– 253, 1956. [2] H. H. Sherief, F. A. Hamza, β€˜β€˜Generalized thermoelastic problem of a thick plate under axi- symmetric temperature distribution’’, Journal of Thermal Stresses, vol. 17(3), pp. 435–452, 1994. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3471 https://internationalpubls.com [3] H. W. Lord, Y. Shulman, β€˜β€˜A generalized dynamical theory of thermoelasticity’’, J. Mech. Phys. Solids, vol. 15, pp. 299–307, 1967. [4] Y. Tanigawa, Y. Komatsubara, β€˜β€˜Theoretical analysis of a rectangular plate and its thermal stress intensity factor compressive stress field’’, Journal of Thermal Stresses, vol. 20, pp. 517–542, 1997. [5] V. M. Vihak, M. Y. Yuzvyak, A. V. Yasinskij, β€˜β€˜The solution of the plane thermoelasticity problem for a rectangular domain’’, Journal of Thermal Stresses, vol. 21, pp. 545–561, 1998. [6] R. J.Adam, C. W. Best, β€˜β€˜Thermoelastic vibrations of a laminated rectangular plate subjected to a thermal shock’’, Journal of Thermal Stresses, vol. 22, pp. 875–895, 1999. [7] T. Morimoto, Y. Tanigawa, R. Kawamura, β€˜β€˜Thermal buckling analysis of an orthotropic nonhomogeneous rectangular plate due to uniform heat supply’’, Nippon Kikai Gakkai Zairyo Rikigaku Bumon Koenkai Koen Ronbunshu, vol. 202, pp. 283–284, 2002. [8] Y. Ootao, Y. Tanigawa, β€˜β€˜Transient thermoelastic problem of functionally graded thick strip due to nonuniform heat supply’’, Composite Structures, vol. 63, pp. 139–146, 2004. [9] L. F. Qian, R. C. Batra, β€˜β€˜Transient thermoelastic deformations of a thick functionally graded plate’’, Journal of Thermal Stresses, vol. 27, pp. 705–740, 2004. [10] J. N. Sharma , P. K. Sharma, R. L. Sharma, β€˜β€˜Behavior of Thermoelastic Thick Plate under Lateral Loads’’, Journal of Thermal Stresses, vol. 27, pp. 171–191, 2004. [11] Y. Z. Povstenko, β€˜β€˜Fractional heat conduction equation and associated thermal stresses’’, Journal of Thermal Stresses, 28, 83–102, 2005. [12] K. R. Gaikwad, K. P. Ghadle, β€˜β€˜Quasi-static thermal stresses in a thick rectangular plate’’, Global Journal of Pure and Applied Mathematics vol. 5(2), 109-117, 2009. [13] H. H. Sherief, A. El-Said, A. Abd El-Latief, β€˜β€˜Fractional order theory of thermoelasticity’’, International Journal of Solids and Structures, vol. 47, pp. 269–275, 2010. [14] K. R. Gaikwad, K. P. Ghadle, β€˜β€˜Three dimensional non-homogeneous thermoelastic problem in a thick rectangular plate due to internal heat generation’’, Southern Africa Journal of Pure and Applied Mathematics, vol. 5, pp. 26–38, 2011. [15] K. R. Gaikwad, K. P. Ghadle, β€˜β€˜Non-homogeneous heat conduction problem and its thermal deflection due to internal heat generation in a thin hollow circular disk’’, Journal of Thermal stresses, vol. 35, pp. 485–498, 2012. [16] K. R. Gaikwad, β€˜β€˜Analysis of thermoelastic deformation of a thin hollow circular disk due to partially distributed heat supply’’, Journal of Thermal stresses, vol. 36, pp. 207–224, 2013. [17] K. R. Gaikwad, β€˜β€˜Mathematical modelling and its simulation of a quasi-static thermoelastic problem in a semi-infinite hollow circular disk due to internal heat generation’’, Journal of the Korean Society for Industrial and Applied Mathematics, vol. 19, pp. 69–81, 2015. [18] V. R. Manthena, N. K. Lamba, G. D. Kedar, K. C. Deshmukh, β€˜β€˜Effects of stress resultants on thermal stresses in a functionally graded rectangular plate due to temperature dependent material properties’’, Int. J. Thermodyn., vol. 19(4), pp. 235-242, 2016. [19] V. R. Manthena, N. K. Lamba, G. D. Kedar, β€˜β€˜Transient thermoelastic problem of a nonhomogeneous rectangular plate’’, Journal Thermal Stresses, vol. 40(5), pp. 627-640, 2017. [20] K. R. Gaikwad, β€˜β€˜Axi-symmetric thermoelastic stress analysis of a thin circular plate due to heat generation’’, International Journal of Dynamical Systems and Differential Equations, vol. 9, pp. 187–202, 2019. [21] K. R. Gaikwad, S. G. Khavale, β€˜β€˜Time fractional heat conduction problem in a thin hollow circular disk and it’s thermal deflection’’, Easy Chair, 1672, 1–11, 2019. [22] F. Yekkalam Tash, B. Navayi Neya, β€˜β€˜An analytical solution for bending of transversely isotropic thick rectangular plates with variable thickness’’, Appl. Math. Model. vol. 77(2), pp. 1582-1602, 2020. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 10s (2025) 3472 https://internationalpubls.com [23] S. G. Khavale, K. R. Gaikwad, β€˜β€˜Generalized theory of magneto-thermo-viscoelastic Spherical cavity problem under Fractional order derivative: State Space Approach’’, Advances in Mathematics: Scientific Journal, vol. 9, pp. 9769–9780, 2020. [24] K. R. Gaikwad, S. G. Khavale, β€˜β€˜Time fractional 2D thermoelastic problem of thin hollow circular disk and it’s associated thermal stresses’’, Bulletin of the Marathwada Mathematical Society, vol. 21(1 & 2), pp. 37-47, 2020. [25] F. Y. Tash, B. N. Neya, β€˜β€˜An analytical solution for bending of transversely isotropic thick rectangular plates with variable thickness’’, Appl. Math. Model., vol. 77(2), pp. 1582-– 1602, 2020. [26] K. R. Gaikwad, Y. U. Naner, β€˜β€˜Analysis of transient thermoelastic temperature distribution of a thin circular plate and its thermal deflection under uniform heat generation’’, Journal of Thermal Stress, vol. 44(1), pp. 75–85, 2021. [27] K. R. Gaikwad, Y. U. Naner, S. G. Khavale, β€˜β€˜Time fractional thermoelastic stress analysis of a thin rectangular plate’’, NOVYI MIR Research Journal, vol. 6(1), pp. 42–56, 2021. [28] S. G. Khavale, K. R. Gaikwad, β€˜β€˜Fractional order thermoelastic problem of thin hollow circular disk and its thermal stresses under axi-symmetric heat supply’’, Design Engineering, vol. 2021(9), pp. 13851–13862, 2021. [29] K. R. Gaikwad, V. G. Bhandwalkar, β€˜β€˜Fractional order thermoelastic problem for finite piezoelectric rod subjected to different types of thermal loading - direct approach’’, Journal of the Korean Society for Industrial and Apllied Mathematics, vol. 25(3), pp. 117-131, 2021. [30] S. G. Khavale, K. R. Gaikwad, β€˜β€˜Analysis of non-integer order thermoelastic temperature distribution and thermal deflection of thin hollow circular disk under the axi-symmetric heat supply’’, Journal of the Korean Society for Industrial and Applied Mathematics, vol. 26(1), pp. 67-75, 2022. [31] K. R. Gaikwad, S. G. Khavale, β€˜β€˜Fractional order transient thermoelastic stress analysis of a thin circular sector disk’’, International Journal of Thermodynamics, vol. 25(1), pp. 1-8, 2022. [32] S. G. Khavale, K. R. Gaikwad, β€˜β€˜2D problem for a sphere in the fractional order theory thermoelasticity to axisymmetric temperature distribution’’, Advances in Mathematics: Scientific Journal, vol. 11(1), pp. 1–15, 2022. [33] S. G. Khavale, K. R. Gaikwad, β€˜β€˜Two-dimensional generalized magneto-thermo-viscoelasticity problem for a spherical cavity with one relaxation time using fractional derivative’’, International Journal of Thermodynamics, vol. 25(2), pp. 89-97, 2022. [34] K. R. Gaikwad, Y. U. Naner, S. G. Khavale, β€˜β€˜Transient thermoelastic bending analysis of a rectangular plate with a simply supported edge under heat source: Green’s function approach’’, Int. J. Nonlinear Anal. Appl., In Press, pp. 1-15, 2022. [35] N. M. Ozisik, Boundary Value Problem of Heat Conduction, International Textbook Company, Scranton, Pennsylvania, 1968. [36] I. N. Sneddon, The use of Integral Transform, McGraw Hill, New York, 1972. [37] I. Podlubny, Fractional differential Equation, Academic Press, San Diego, 1999. [38] B. G. Korenev, Bessel Functions and Their Applications. Boca Raton: CRC Press, 2003. [39] Y. Z. Povstenko, Fractional Thermoelasticity, New York: Springer, 2015. [40] PTC Mathcad Prime-7.0.0.0, [Online]. Available: https://support.ptc.com/help/mathcad/r7.0/en/ (accessed Sep. 1, 2022).