Projects

​​Project Title ​FE modelling of porous structures using Selective laser melting
​Group Members ​Hamza Ali
​​Project Supervisor(s) ​​Dr Khalid Mahmood
​Project Abstract ​Selective laser melting is the branch of additive manufacturing in which parts are made layer by layer using laser beam as a heat or energy source to melt the powder layers and manufacture the part according to the CAD model. It has the ability to manufacture highly complex parts which are very difficult to manufacture using conventional techniques. SLM is very popular technique to manufacture orthopaedic implants for the medical industry. If the human bone is damaged, then orthopaedic implants can be installed as a substitute in the human body to ensure quality life for the person. Implants manufactured using SLM have very high elastic modulus as compared to human bone which can cause stress shielding and damage the human bone and so elastic modulus of the implants needs to be lowered. For this purpose, in this research work, we have designed many implants using gyroid and diamond TPMS structures that have elastic modulus close to the human bone, are biocompatible and have good mechanical properties. All the implant designs were inspected and their results were compared and validated with the existing literature. All the designed implants in this research work meet the requirements of an ideal orthopaedic implant and can be physically installed in the human body.
​​Project Title ​Numerical Analysis on Crashworthiness Design of Thin Walled Columns under Dynamic Impact Loading Conditions
​Group Members Sajjad Hussain
​​Project Supervisor(s) Dr Syed Gul Hassan Naqvi
​Project Abstract ​Transportation and automobiles have become a part of our daily lives and the risks associated with them of unwanted collision have also increased with automobiles being manufactured at a very high level all over the world. With the increasing trend of fatalities and injuries caused by the road traffic accidents, making the vehicles safer has become more critical. In the early years vehicle were made of solid metals and heavy frames which provided enough occupant protection but with time the need of making vehicles fuel efficient the low weight requirement has changed the manufacturing era of automobiles. Although we cannot avoid the occurrence of unwanted collisions but the impact and severity of crash can be reduced. Thin Walled Columns are extensively being used in various engineering applications for the purpose of safety requirements due to their high energy absorption capacity. Their primary purpose is to absorb the excess amount of impact energy during an unwanted collision undergoing deformation. Numerical analysis of crushing behavior using Finite Element Module LS-DYNA is carried out to study the best performance parameters which are specific energy absorption (SEA), mean crushing force (MCF) and low peak force (PF) by varying different design variables including cross sectional geometry, thickness and length. The objective is to find the best optimal crash box which undergoes progressive deformation to absorb collision energy for the application in automobiles to enhance the safety for passenger cabin. To study the effect of number of corners on crashworthiness parameters, polygons having 5 to 8 corners are numerically analyzed and the best of them is further numerically investigated with circular, rectangle and square cross sectional shape. Thin walled tube having hexagonal cross section is found to be the best for energy absorption under axial impact loading while comparing selected crashworthiness parameters.

Key Words: Crashworthiness, Thin walled tube, Finite element method, Mean crushing force, Specific energy absorption, Peak force

​​Project Title ​Investigation of Effect of Multiple Stepping and Curvature on Metallic Tubes for Crashworthiness Parameters and Energy Absorption Applications
​Group Members Ammara Mustafa
​​Project Supervisor(s) Dr Hasan Aftab Saeed
​Project Abstract ​Crashworthiness of the structure is the most crucial concern in modern day automobile and aerospace industry, in order to protect the occupants, payload, sensitive equipment and the environment in case of any fatal crash situation. Light weight, cost effective and efficient thinwalled energy absorbing structures are the optimal choice to serve the purpose with enhanced crashworthiness characteristics while under dynamic crushing. The characteristics of energy absorption are size, cross-sectional geometry, material and boundary condition dependent for thin-walled structures. Thin metallic tubes proved themselves as efficient energy absorbers and have been in extensive use for many aerospace and automotive applications to improve the structure crashworthiness. Crashworthiness parameters may be improved through multi-cells arrangement, multiple cross-sectional features, functional gradient characteristics, addition of triggers and foam or honeycomb filling. Stepping in tube’s structure can provide energy absorption with progressive failure as per a design’s specific requirement; however, geometry parameters may influence their performance capabilities. Another important parameter is curvature of the surfaces or corners which may increase the critical buckling load and may guide buckling initiation and propagation. In this study, stepped tubes sensitivity with geometric variation and curvature effects are investigated on energy absorption characteristics of metallic tubes for circular and square tubes; with and without addition of curvature for square tubes and also with curved multi-cells stiffeners along the radial and axial direction and unconventional arrangements of bi-tubular arrangements with and without curvature. A number of geometry arrangements are studied and the effects of adding stepping and curvature are studied for their deformation and energy absorption characteristics. Different parameters such as mean crushing force, peak crushing force and specific energy absorption are determined and discussed for all of the proposed configurations. The proposed arrangements show a relatively stable crushing behavior and high crush force efficiency. In the final part, a robust decision making technique.

The COmplex PRoportional ASsessment (COPRAS) is applied to the proposed configurations for determination of curvature effects in order to find the best configuration which is based on the amount of energy absorbed, low crushing force and high crush force efficiency.

Key Words: Crashworthiness, Step-tubes, Multi-cell tubes, Curvature, Energy absorption,

Dynamic Crushing

​​Project Title ​WIND SPEED ESTIMATION USING ARTIFICIAL NEURAL
​Group Members Zeeshan Ali Cheema
​​Project Supervisor(s) Dr Imran Shafi
​Project Abstract ​Crashworthiness of the structure is the most crucial concern in modern day automobile and aerospace industry, in order to protect the occupants, payload, sensitive equipment and the environment in case of any fatal crash situation. Light weight, cost effective and efficient thinwalled energy absorbing structures are the optimal choice to serve the purpose with enhanced crashworthiness characteristics while under dynamic crushing. The characteristics of energy absorption are size, cross-sectional geometry, material and boundary condition dependent for thin-walled structures. Thin metallic tubes proved themselves as efficient energy absorbers and have been in extensive use for many aerospace and automotive applications to improve the structure crashworthiness. Crashworthiness parameters may be improved through multi-cells arrangement, multiple cross-sectional features, functional gradient characteristics, addition of triggers and foam or honeycomb filling. Stepping in tube’s structure can provide energy absorption with progressive failure as per a design’s specific requirement; however, geometry parameters may influence their performance capabilities. Another important parameter is curvature of the surfaces or corners which may increase the critical buckling load and may guide buckling initiation and propagation. In this study, stepped tubes sensitivity with geometric variation and curvature effects are investigated on energy absorption characteristics of metallic tubes for circular and square tubes; with and without addition of curvature for square tubes and also with curved multi-cells stiffeners along the radial and axial direction and unconventional arrangements of bi-tubular arrangements with and without curvature. A number of geometry arrangements are studied and the effects of adding stepping and curvature are studied for their deformation and energy absorption characteristics. Different parameters such as mean crushing force, peak crushing force and specific energy absorption are determined and discussed for all of the proposed configurations. The proposed arrangements show a relatively stable crushing behavior and high crush force efficiency. In the final part, a robust decision making technique.

The COmplex PRoportional ASsessment (COPRAS) is applied to the proposed configurations for determination of curvature effects in order to find the best configuration which is based on the amount of energy absorbed, low crushing force and high crush force efficiency.

Key Words: Crashworthiness, Step-tubes, Multi-cell tubes, Curvature, Energy absorption,

Dynamic Crushing