<p>As we know that nature made the things optimized in all point of views, also it is supposed that nature works under some evolutionary process.</p><p>Since there was no such Evolutionary Structural Optimization (ESO) method having strong mathematical background, that’s why these are not much reliable. The purpose of this thesis work is a little effort to introduce such an ESO method having a strong mathematical background.</p><p>In this thesis work Optimization as a thermodynamic system, we are introducing a new method for topology optimization by using concept of Free Energy and Dissipation Potential from non-smooth thermodynamics system. For better understanding we may call it as Evolutionary Structural Topology Optimization (ESTO), and this project work is done in the following steps.</p><p>An evolution problem is formulated in terms of free energy and dissipation potential for a non-smooth thermodynamical system. Free energy is taken as an objective function for a general structural optimization problem. Derivation of a well posed evolution problem for which evolution is such that objective function always decreases. An optimality criteria method is derived for given evolution problem and it is implemented in a FEM program TRINITAS. And the behaviour of the so called evolutionary parameters such as Forward and Backward plastic constants is analyzed.</p>

As we know that nature made the things optimized in all point of views, also it is supposed that nature works under some evolutionary process. Since there was no such Evolutionary Structural Optimization (ESO) method having strong mathematical background, that’s why these are not much reliable. The purpose of this thesis work is a little effort to introduce such an ESO method having a strong mathematical background. In this thesis work Optimization as a thermodynamic system, we are introducing a new method for topology optimization by using concept of Free Energy and Dissipation Potential from non-smooth thermodynamics system. For better understanding we may call it as Evolutionary Structural Topology Optimization (ESTO), and this project work is done in the following steps. An evolution problem is formulated in terms of free energy and dissipation potential for a non-smooth thermodynamical system. Free energy is taken as an objective function for a general structural optimization problem. Derivation of a well posed evolution problem for which evolution is such that objective function always decreases. An optimality criteria method is derived for given evolution problem and it is implemented in a FEM program TRINITAS. And the behaviour of the so called evolutionary parameters such as Forward and Backward plastic constants is analyzed.

<p>Models of human musculoskeletal tissue are the missing component needed to make significant advances in clinical orthopedics. Developing these models requires an in-depth knowledge of techniques and procedures which are rarely considered or taught in universities.  Essential skills like deriving the foundational physics and the constitutive theory from first principles are the building blocks which will deliver future models or ligaments, tendons, and muscles. This thesis presents the first step in a journey to understand these modeling techniques in order to move toward developing a model of human tissue. The material utilized in the experiments</p> <p>was recipe of Ecoflex 00-20 which represents an idealized example of a large deformation viscoelastic solid. The Finite Strain Viscoelastic constitutive law was derived from first principles, uni-axial tension experiments provided the raw data, and the constitutive laws were fit to the data. The derived model outperformed most of the models with some exceptions described in the results. These results justify the development of more complicated models and experiments such as modeling surface field data and considering more complicated material properties.</p>

This thesis explores the science of solid mechanics via the theory of peridynamics. Peridynamics has several key advantages over the classical theory of elasticity. The most notable of which is the ease with which fractures in the the material are handled. The goal here is to study the two theories and how they relate for problems in which the classical method is known to work well. While it is known that state-based peridynamic models agree with classical elasticity as the horizon radius vanishes, similar results for bond-based models have yet to be developed. In this study, we use numerical simulations to investigate the behavior of bond-based peridynamic models under this limit for a number of cases where analytic solutions of the classical elasticity problem are known. To carry out this study, the integral-based peridynamic model is solved using the finite element method in two dimensions and compared against solutions using the classical approach. / Master of Science

For automotive plastic parts there is a clear demand on an increased quality of the FE models. This demand is related to the increased use of simulations, both due to a reduced number of prototypes and an increased number of load cases. There have been studies showing a change of dynamic properties in injection molded components. The conclusion from these studies are that the change depends on residual stresses built in during the injection process. This study use simple models to try to get a working method and from the results find out the basic relations between residual stresses and dynamic properties. A method was developed and the results showed that the residuals had a major impact on the dynamic properties. Continuation on this work would be to use more complex models, to try to mimic results from reference studies and tests.

This work aims at providing a numerical tool for the efficient design of the multidirectional carbon fiber reinforced composite material by means of finite element simulations. Abaqus/ CAE v 6.9-1 software has been used to establish a 3D model for simulation of the tensile test on the composite specimen. The aim of this analysis of multidirectional carbon fiber reinforced composite is to predict the strain and stress distribution in different plies through thickness. Tensile test experiment was carried out and the result was analyzed by ARAMIS to calculate the young’s modulus, stress, loads and strain of the composite specimen. The numerical model was compared against the result obtained from tensile test experiment to arrive at meaningful results for validation. This is done in order to understand the mechanical strength and strain at failure of the composite material. In this work three types of CFRP composite specimens are used, all have same 15 no. of ply but stacked in different orientation. It is found out that mechanical strength, failure load and strain differ slightly depending on this different ply orientation. A series of different modeling technique has also been done to verify the best modeling technique. The micromechanics of composite material is complex and the experimental predictions are time consuming and expensive. Though using FEM frequently solves the problem.

The design and analysis of drop test to investigate the behaviour of adhesive joints in automotive structures is performed. The drop test is simulated by FE software. The specimen geometry is based on Volvo Car Corp. drop test standard. In the drop test machine, a general beam structure is supporting all the parts. The machine includes a lifting system. The test is applied to a pre designed specimen, which will provide the information about adhesive joint strength.

<p>The design and analysis of drop test to investigate the behaviour of adhesive joints in automotive structures is performed. The drop test is simulated by FE software. The specimen geometry is based on Volvo Car Corp. drop test standard.</p><p>In the drop test machine, a general beam structure is supporting all the parts. The machine includes a lifting system. The test is applied to a pre designed specimen, which will provide the information about adhesive joint strength.</p>

The project was part of Airbus' drive to reduce the weight of the parts making up the Hinge 2 in the Keel Beam section of the A350 XWB-1000 by 15 kg. Although optimisation only led to a weight reduction of 4.5 kg, it was still decided to carry out a derisking study of the Hinge. To do this, the parts making up the Hinge had to be modelled in 2D and 3D finite elements using Hyperworks and according to the necessary meshing rules. This new mesh then had to be integrated into an overall mesh of the entire section of the Keel Beam. After recovering the critical safety margins and their loads from the certification files, it was necessary to run these loads on the new model in order to extract the dimensioning forces. These loads were then used to carry out the priority static studies using Hyperworks, Excel and Isami. Nine studies were carried out to ensure that the new geometry of the Hinge would hold up well. In the end, despite constraints such as the absence of contacts in the model studied, no safety margin fell below 1, which validates the static strength of the new Hinge. Finally, this project was very instructive, both personally and professionally, leading to become nearly completely autonomous as a calculation engineer. / Projektet var en del i Airbus strävan att minska vikten på gångjärnsdelar i en kölbalkssektion på A350 XWB-1000 med 15 kg. Även om endast 4,5 kg kunde reduceras i slutändan, genom optimering, beslutades det att genomföra en analys av gångjärnet för riskminimering. För detta modellerades de delar som utgör gångjärnet med 2D och 3D finita element i Hyperworks, under iakttagande av gällande rekommendationer för meshning. Beräkningsnätet behövde sedan integreras i ett övergripande nät för hela sektionen av kölbalken. Efter att ha hämtat de kritiska säkerhetsmarginalerna och deras belastningar från certifieringsfiler var det nödvändigt att analysera dessa belastningar i den nya modellen för att få fram de dimensionerande krafterna. Dessa laster användes sedan för att utföra de prioriterade statiska studierna med hjälp av Hyperworks, Excel och Isami. Nio studier utfördes för att säkerställa att gångjärnets nya geometri skulle uppfylla kraven. Analysen validerade den statiska styrkan hos det nya gångjärnetI, med reservation för begränsningar såsom avsaknaden av kontaktmodellering i den använda modellen. Ingen säkerhetsfaktor överskreds. Projektet var mycket lärorikt, både på det personliga och yrkesmässiga planet, till den punkt där jag blev praktiskt taget självständig som beräkningsingenjör.

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