Paper Title

FINITE ELEMENT ANALYSIS OF FATIGUE CRACK GROWTH IN ADVANCED METAL ALLOYS

Abstract

The analysis of fatigue crack growth is carried out within the framework of the classical linear elastic fracture mechanics. The preprocessing and the finite element analysis of the cracked structure are done using the commercial software system Abaqus. Elastic-perfectly plastic constituents, each with random yield strength, modeled by a normal probability density function are used. Complex constituent relations for material behavior under monotonically increasing load or cyclic loading are replaced by a probabilistic approach in the developed finite element program. The software system ProCrack, a Python-based tool for the automated finite element simulation of fatigue crack growth in arbitrarily loaded three-dimensional components is presented. The Bauschinger effect is found to be related to the mean and the hardening coefficient to the variance of the distribution. The decomposed global stiffness matrix is updated using an efficient technique instead of reformulating it after each boundary change. The applied strains are so important that diffuse damage phenomena are visible as a network of micro-cracks in front of the major crack. A sub-modelling technique in combination with the interaction integral techniqueis used to calculate the range of the stress intensity factors. Fatigue crack growth behavior in weld nugget zone (WNZ) of friction stir welded (FSWed) dissimilar aluminum alloys joints were investigated comparing to that of the FSWed similar aluminum alloy joints and the base materials.
KEYWORDS : Fatigue crack growth, weld nugget zone (WNZ), aluminum alloys, cracked structure, plastic constituents, micro-cracks, materials.

Paper Title

OPTIMIZATION AND SIMULATION OF COMPOSITE FIBER CONFIGURATIONS FOR AEROSPACE APPLICATIONS

Abstract

This study investigates the composite materials used in Aircraft structure and also reviews the advanced composites as structural materials. At present composites material are becoming important in Aerospace engineering due to its increased strength at lower weight, stiffness and corrosion resistance. For the Aerospace Engineering there are huge progress of material science and engineering with the technological challenges in terms of the development of sophisticated and specialized materials e.g composite materials. Composites materials are intended to be used more extensively as an alternative of aluminum structure in aircraft and aerospace applications. This is due to their attractive properties as high strength-to-weight ratio and stiffness-to-weight ratio. Besides that it clarifies the growing interest for composites materials due to advantages of lightweight, high strength, high stiffness, superior fatigue life, tremendous corrosion resistance and low cost manufacturing. In this study, a finite element analysis (FEA) of fiberglass unidirectional Etype was analyzed in the framework of ABAQUS finite element commercial software. The analysis was done to quantify the mechanical properties and response of unidirectional E-glass in term of tensile, compression and thermal responses.
KEYWORDS : Aircraft structure, composites as structural materials, aerospace, stiffness-to-weight ratio, high stiffness, E-glass.

Paper Title

EXPLORING THE CHARACTERIZATION AND GROWTH OF ORGANIC AND SEMI-ORGANIC MATERIALS

Abstract

A new semi-organic nonlinear optical thiosemicarbazide cadmium acetate (TSCA) material has been synthesized. TSCA single crystals were grown from aqueous solution by slow evaporation method. The solubility of TSCA has been determined for various temperatures. The grown crystals were characterized by single crystal X-ray diffraction (XRD), FTIR, UV-Vis., thermal and second harmonic generation (SHG) analysis. Single crystal XRD study has been carried out to identify the lattice parameters. FTIR studies confirm the functional groups present in the grown crystal. Optical transmission studies have confirmed that the grown crystal is highly transparent. Thermogravimetric and differential thermal analyses reveal the good thermal stability of the material. The SHG conversion efficiency of TSCA was determined using Kurtz powder technique and found two times that of potassium dihydrogen orthophosphate (KDP).
KEYWORDS : Growth from solution, Semi organic, Nonlinear optical crystal

Paper Title

LEAN CONSTRUCTION: A TIME AND COST SAVING METHOD FOR MANAGING PROJECT

Abstract

Projects are thought of as transient production systems that must be planned, created, and delivered within a certain window of time. Many scholars have argued that fast-track projects with intricate, lengthy supply chains cannot be handled in the traditional manner because they are complex, fast-moving, and unpredictable. Engaging several parties and undergoing numerous, significant process design modifications have complicated flow management that has utterly failed. The work breakdown structure, critical path technique, and earned value management are some of the tools and conceptual models of construction management that have come under fire for not being able to adequately handle the current, particular issues that projects face. Consequently, a multitude of wastes are characteristic of this business, such as overproduction, lead times, transportation, improper processing, inventories, needless movements, rework, and making do wastes. Therefore, in order to assist project teams in addressing the problem of wastes in projects, it is necessary to develop reliable and useful models and methodologies. Lean Construction (LC), or the use of lean production processes in the construction sector, is the only way to do this. This essay discusses the LC approach as a reliable project management methodology and the significance of putting it into practice.
KEYWORDS : Lean Construction, Project Management, Time and Cost Saving.

Paper Title

A STUDY ON THE CHARACTERISTICS OF GEOPOLYMER MORTAR

Abstract

Concrete experts have lately been using breakthrough geopolymer technology to generate new environmentally friendly construction materials. Geopolymer mortar (GPM) is created via the method of geopolymerization, which involves producing a geopolymeric binder by the alkali-activation of a precursor that is rich in aluminosilicate. This is done by utilizing alkali activators at room temperature and adding fine aggregates of sand. The properties and applications of geopolymer mortar are the subject of interest among civil engineers and material scientists. This is due to its remarkable attributes and its potential to address the sustainability issue of carbon dioxide emission caused by the current production process of ordinary Portland cement (OPC). Geopolymer mortar also offers advantages such as the ability to incorporate various waste materials in the manufacturing of geopolymer products. This article provides a summary of the latest characteristics of geopolymer mortar, including its workability, setting time, and surface temperature. The results showed that the geopolymer mortar has significant potential and many applications for use in eco-constructions. It might serve as a viable alternative to traditional cement in the future.
KEYWORDS : Geopolymer, Geopolymer Mortar, Characteristics.