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The determination of stress intensity factors (SIF) is of fundamental importance in prediction of brittle failure using linear elastic fracture mechanics. The presence of a crack in the vicinity of another crack induces an interaction effect. The purpose of this paper is to determine the SIF for an orthotropic lamina subjected to uniaxial loading and containing two cracks. The solution is obtained for one crack being horizontal and located in the centre of lamina while the other crack is inclined to first one. The effect of angle of the second crack, fibre angle is studied. Also, for the case of two parallel cracks, effect of eccentricity in x and y directions is observed.

Boundary collocation method is used and stress functions satisfying governing equations in the domain and ensuring stress singularity at the crack tips are defined. The boundary condition on the edges of lamina and the crack is satisfied to determine the complex coefficients in the stress functions.

For the given fibre angle, orientations of second crack which result in increase/decrease in the SIF at the most dangerous crack tip are found out.

Boundary collocation method which is simple and efficient is extended for studying two crack problem in orthotropic materials.

The purpose of this paper is to use the natural wastage plant product, bannana pseudostem sap (BPS) for using as fire retardant of cellulosic textile substrate. The study aims to use first time any wastage plant product for making fire retardant cellulosic textile. In this regard flame retardant functionality was imparted in cellulosic textile using BPS, an eco-friendly natural wastage product.

The extracted sap was made alkaline and applied in pre-mordanted bleached and mercerized cotton fabrics. Flame retardant properties of the control and treated fabrics were analyzed in terms of limiting oxygen index (LOI), horizontal and vertical flammability and total heat of combustion using bomb calorimeter. The thermal degradation and pyrolysis was studied using thermogravimetric analysis (TGA). The chemical composition of the control and BPS treated cellulosic fabric were analyzed by FTIR, SEM and EDX. Durability of the flame retardant functionality to soap washing had also been studied.

The study showed that the treated fabrics had good flame retardant property compared to control fabrics. The LOI value was found to increase by 1.6 times after application of BPS. As a result of this, the fabric does not catch flame. In horizontal flammability, the treated fabric showed burning with afterglow (without presence of flame) with a propagation rate of 7.5 mm/min, which is almost ten times lower than the control fabric. After application of BPS cellulosic fabric sample produced natural khaki colour. There was no significant change in other physical properties.

The application process is simple and cost-effective as no costly chemicals were used. Further advantage is that the treated fabric could also be considered as natural dyed cotton fabric. The developed khaki colour is quite attractive and stable to sun light exposure. This developed process could used in colouration and flame retardant finishing of home furnishing products such as home-window curtain, railway curtain, hospital curtain, table lamp and as a covering material of non-permanent structure like in book fair, festival, religious purpose, etc., where large quantity of textile is used and has chance of fire hazards.

BPS abundantly available in Indian as well as other countries and it is normally considered as waste material. It is eco-friendly and produced from renewable source. Therefore, the application of BPS in cotton textile for colouration and functionalization will give the advantages of value addition using natural product. Rural people will be benifited lot by applying this technology whenever it required.

This paper helps to clarify first time why and how a wastage plant product like BPS can be used for preparing fire retardant cotton cellulosic fabric.

The purpose of this paper is to present the surface roughness effects on mixed convection nanofluid flow with liquid hydrogen/liquid nitrogen diffusion.

The small parameter (α) is considered along with the frequency parameter n to study the surface roughness. The non-similar transformations are used to reduce the dimensional non-linear partial differential equations into dimensionless form, and then, the resulting equations are solved with the help of Newton’s Quasilinearization technique and the finite difference scheme.

The impacts of several dimensionless parameters such as Brownian diffusion parameter (Nb), thermophoresis parameter (Nt), small parameter (α), etc., are analyzed over various profiles as well as gradients. Also, the investigation is carried out for in presence and absence of nanoparticles. The influence of surface roughness is sinusoidal in nature and is more significant near the origin in case of skin-friction coefficient. The addition of nanoparticles enhances the skin-friction coefficient and reduces the Nusselt number, while its effects are not noticeable in case of mass transfer rates. The presence of suction/blowing, respectively, enhances/decreases the Sherwood number pertaining to the liquid hydrogen.

The results of the present analysis are expected to be useful for the design engineers of polymer industries in manufacturing good quality polymer sheets.

To the best of the author’s knowledge, no such investigation has been carried out in the literature.

This paper aims to investigate the influence of “BroncoCut-X” (copper core-ZnCu50 coating) electrode on the machining of Ti-3Al-2.5V in view of its extensive use in aerospace and medical applications. The machining parameters are selected as Spark-off Time (ST_off), Spark-on Time (ST_on), Wire-speed (S_w), Wire-Tension (WT) and Servo-Voltage (S_v) to explore the machining outcomes. The response characteristics are measured in terms of material removal rate (MRR), average kerf width (KW) and average-surface roughness (SA).

Taguchi’s approach is used to design the experiment. The “AC Progress V2 high precision CNC-WEDM” is used to conduct the experiments with ϕ 0.25 mm diameter wire electrode. The machining performance characteristics are examined using main effect plots and analysis of variance. The grey-relation analysis and fuzzy interference system techniques have been developed to combine (called grey-fuzzy reasoning grade) the experimental response while Rao-Algorithm is used to calculate the optimal performance.

The hybrid optimization result is obtained as ST_off = 50µs, ST_on = 105µs, S_w = 7 m/min, WT = 12N and S_v=20V. Additionally, the result is compared with the firefly algorithm and improved gray-wolf optimizer to check the efficacy of the intended approach. The confirmatory test has been further conducted to verify optimization results and recorded 8.14% overall machinability enhancement. Moreover, the scanning electron microscopy analysis further demonstrated effectiveness in the WEDMed surface with a maximum 4.32 µm recast layer.

The adopted methodology helped to attain the highest machinability level. To the best of the authors’ knowledge, this work is the first investigation within the considered parametric range and adopted optimization technique for Ti-3Al-2.5V using the wire-electro discharge machining.