Informatics Publishing Limited

K. Sathyanarayana ¹, V. Sandeep ¹, K. R. Pradeep ¹, D. Sujib ¹, K. Ravindra ¹, G. V. V. Ravi Kumar ¹

Affiliations
1 Engineering Services, Infosys Limited, Electronic City, Bangalore, IN

Abstract

Composites structures are widely used both in military and commercial aircraft industries. Design of tapered composite skins is quite laborious and time consuming. Optimization of these composite skins is essential for realizing the full benefits offered by composites. Composite skins are optimized in two stages. In the first stage, thicknesses of various zones of composite skin along with the percentage of fiber orientations is computed using gradient based algorithms. In the second stage, the stacking sequence generation is performed mostly using knowledge based engineering approaches using rules and heuristics. The stacking sequence generation is a combinatorial problem and is quite complex. Such combinatorial problems can be solved elegantly by genetic algorithms. The available genetic algorithm based stacking sequence approaches are mostly theoretical and are demonstrated mainly as research and academic problem for laminates of constant thickness with few constraints. In this paper a genetic algorithm based approach for stacking sequence generation of tapered composite skins with multiple zones is presented. This approach is scalable and can solve large size composite skin generation problems with reasonably good number of constraints. The paper also demonstrates the usefulness of the current approach by solving few large scale stacking sequence generation problems in real life aircraft industry.

Keywords

Composite Wing, Stacking Sequence Optimization, Aircraft Structures, Genetic Algorithms.

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B. THIRUPAM REDDY ¹, M. CHANDRASHEKHARAIAH ², B. RAGHAVENDHAR ³, D. M. BAWASKAR ⁴, C. SELVARAJ ⁵, S. M. MAZUMDAR ⁶, G. V. VISHAKA ², H. A. NADAF ², M. S. RATHORE ², K. SATHYANARAYANA ²

Affiliations
1 Basic Seed Multiplication and Training Centre, Kharsawan –833216, Jharkhand, IN
2 Basic Tasar Silkworm Seed Organization, Central Silk Board, Bilaspur – 495112, Chhattisgarh, IN
3 Department of Entomology, Professor Jayashankar Telangana State Agricultural University, Hyderabad - 500030, Telangana, IN
4 Basic Seed Multiplication and Training Centre, Balaghat – 481001, Madhya Pradesh, IN
5 Basic Seed Multiplication and Training Centre, Madhupur – 815353, Jharkhand, IN
6 Basic Seed Multiplication and Training Centre, Kathikund – 814103, Jharkhand, IN

Abstract

Studies have been carried out on exploration of natural enemies of the Psyllid bug, Trioza flecheri minor on Terminalia spp., the primary host plantations of tasar silkworm during April to November, 2020. The results of the studies indicated that among the natural enemies recorded on T. flecheri minor, the Trechnites aligarhensis Hayat, Alam and Agarwal was the major encyrtid parasitoid. The incidence of T. f. minor was significantly more on T. arjuna (22.98% galls) compared to T. tomentosa (12.59% galls) and peak incidence was observed during the August and September months. The parasitization of T. aligarhensis on T. f. minor was significantly more on T. arjuna (33.13%) as compared to T. tomentosa (24.92%).

Keywords

Galls, parasitisation, Tasar silkworm, Trechnites aligarhensis, Trioza flecheri minor.

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