Safety is of paramount importance to manufacturers of roadway vehicles. Although in the past few years much progress has been made in the field of passenger safety in cars, there is still a strong need for the design of a more crashworthy vehicle in a frontal collision. Therefore, a vehicle crash test performance and how well the vehicle protects the front seat passengers in a head-on-collision is an essential part of the design of the vehicle. Over the past twelve years, the modeling of components and crash analysis of entire vehicles have become increasingly significant. In this thesis, a Ford Taurus model is analyzed in a frontal full-width and offset impact. This thesis describes the comparison of structural damage on a vehicle colliding with rigid pole as compared to the same vehicle model colliding with a barrier. The reason for selecting a rigid pole was to consider the worst-case scenario. The NHTSA has rules and regulations for barrier crashes; however it does not have any standards for pole crashes. In reality, there are many pole related vehicle crashes every year. Pole crashes involve vehicles colliding with utility and traffic light poles. Our purpose was to study the intrusion and injury values for the pole test and compare it with the barrier testing method of NHTSA. These simulations are carried under the New Car Assessment Program (NCAP) and the Insurance Institute for Highway Safety (IIHS). The simulations are obtained using LS-DYNA3D crash code. The rigid barrier, deformable barrier and pole are modeled in MSC/PATRAN. The accelerations at various points are recorded. The occupant compartment intrusions are compared between pole and barrier. Finally the responses of an occupant for the crash tests are studied in Mathematical Dynamical Models (MADYMO) by placing the dummy inside the dyna model. The dummy is placed in the car using extended coupling. A hybrid III 50th percentile male dummy model is used to study the occupant responses. The finite element shoulder and lap belts are modeled in MADYMO. The head accelerations are plotted and the HIC values are calculated. For the crash test the occupant foot injury during compartment intrusion is evaluated by calculating the tibia index and tibia forces. The barrier and the pole test results are compared and the results showed that the intrusions and injury values are more severe in the case of pole impact and in off-set crash there is a severe leg injury. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering. / "December 2005."

Roadside safety hardware has traditionally been approved on the basis of full-scale crash tests. In recent years, nonlinear dynamic Finite Element (FE) programs like LS-DYNA, PAM-Crash or ABAQUS Explicit have been widely used in evaluating new or improved design of roadside hardware. Although a powerful tool, numerical models must be properly verified and validated in order to provide reliable results. Typically, the verification and validation (V&V) process involves a visual comparison of two curves and is based on a purely subjective judgment. This research investigated the use of comparison metrics, which are mathematical measures that quantify the level of agreement between two curves, for comparing simulation and experimental outcomes in an objective manner. A computer program was developed in Matlab® to automatically evaluate most of the comparison metrics available in literature. The software can be used to preprocess and compare either single or multiple channels, guiding the user through friendly graphical interfaces. Acceptance criteria suitable to represent the typical scatter of experimental tests in roadside safety were determined by comparing ten essentially identical full-scale vehicle crash tests. The robustness and reliability of the implemented method were tested by comparing the qualitative score of the computed metrics for a set of velocity waveforms with the corresponding subjective judgment of experts. Moreover, the implemented method was applied to two real validation cases involving a numerical model in roadside safety and a model in biomechanics respectively. Eventually, the program showed to be an effective tool to be used for assessing the similarities and differences between two curves and, hence, for assisting engineers and analysts in performing verification and validation activities objectively.

This thesis deals with documentation and analysis of the most common types of vehicle damage caused by collisions with fixed objects at low speeds. The characteristic damage analysis is based on performing custom crash tests using objects that are different in shape and material. Furthermore, the thesis deals with the comparison of performed crash tests with vehicle damage typical for collisions of two vehicles in so-called parking maneuvres. The analysis is then applied in the assessment of real traffic accidents, which were identified as insurance frauds during the investigation. The work can be further used as a basis for comparative databases.

The aim of this master’s thesis was to create a component model of a door handle stiffener used by the Volkswagen concern, which can be used for crash computations. Also to tune its parameters the way, its behavior corresponds the most to the real part’s. In the theoretical part the current regulations of the Euro NCAP are presented, concerning the testing and evaluation of the passive safety of new vehicles. Attention is focused on the evaluation of the side impact barrier tests, where the effect of the door handle stiffener’s damage is reflected the most. Shown are the reasons for the effort to simulate the real behavior of the stiffener, the factors, which initialized the born of the studied problem. The practical part starts with the creation of the FEM mesh of the part based on its 3D CAD model, also describes the requirements for the mesh quality, as well as the used tools and methods. Further on investigated are the characters of real damages of the door handle area during side impacts, based on which the component tests are proposed for the validation of the simulation model. Experimental research consists of the stiffener’s testing for simple bend and twist loads, three specimens each. After the execution of the tests the results get compared with the corresponding simulations. Modifications are made on the model according to the acquired results: refinement of the FEM mesh, new material model usage with failure for shell elements and definition of real material characteristics for the used thermoplastics. The latest obtained simulation dependencies are compared with the measured values again, the results are evaluated at last.

Till följ av de stora skadorna som riskeras vid frontalkollision mellan personbil och lastbil, utför Scania CV AB kraschtester för att bättre kunna utveckla komponenter med syfte att skydda passagerarna i personbilen. Den typ av test som denna studie bygger på utvärderar den s.k. FUP:en (engelska Front Underrun Protection). I dagsläget görs ett fullskaligt test, där en personbil avfyras in i en lastbil. Syftet med studien är att undersöka möjligheten att utveckla en förenklad test metod där endast de väsentliga komponenterna från lastbilen inkluderas, och en representativ struktur ersätter personbilen. Om möjligt kommer detta minska kostnaderna samt möjliggöra för större repeterbarhet. Tester och utvärderingar görs med hjälp av simulationer i LS-Dyna, ANSA & META, och designkoncept visualiseras i CAD-programmet CATIA V5. Resultat visar att det finns goda förutsättningar för att ersätta personbilen med en barriär av honeycomb struktur samt att lastbilen kan ersättas med en vagn där de väsentliga komponenterna fäst. Diskussioner kring simuleringarna och designen lyfter fram faktorer som visar på goda utvecklingsmöjligheter, men med betoning på det fortsatta arbetet som krävs. / Scania CV AB are developing components to prevent fatal damages during frontal collisions with passenger cars. Therefore, they need to test their assemblies and specifically FUP (Frontal Underrun Protection). Currently, a full-scale test is done in which a passenger car is launched into a truck. The purpose of this study is to examine and develop the possibility of having a simplified test procedure in which only the relevant components of the truck are included, and a representative structure replaces the car. If possible, this would reduce costs and allow for greater repeatability. Analysis and evaluations are done via finite element models using ANSA, LS-Dyna and META. The conceptual design is visualized using CATIA V5. Results show good indication that the passenger car can be replaced by a trolley with deformable barriers mounted on it and the truck can be replaced by a simplified structure with main FUP components mounted onto it. Discussions about the numerical models results and the conceptual design highlight factors that show promising possibilities, but with emphasis on the continued work that is required.

Submitted in fulfillment of the requirements for the degree of Doctor of Engineering: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2017. / The development and validation of reliable numerical modelling approaches is important for higher levels of aircraft crashworthiness performance to meet the increasing demand for occupant safety. With the use of finite element analysis (FEA), development costs and certification tests may be reduced, whilst satisfying aircraft safety requirements. The primary aim of this study was the development and implementation of an explicit nonlinear dynamic finite element based methodology for investigating the crashworthiness of a small lightweight fibre reinforced composite aircraft with occupants. The aircraft was analysed as it crashed into soft soil and the FEA software MSC Dytran was selected for this purpose. The aircraft considered for the purposes of this study was based on a typical four-seater single engine fibre-reinforced plastic composite aircraft. The definition of a survivable accident is given by Coltman [1] as: “an accident in which the forces transmitted to the occupant through his seat and restraint system do not exceed the limits of human tolerance to abrupt accelerations and in which the structure in the occupant’s immediate environment remains substantially intact to the extent that a liveable volume is provided for the occupants throughout the crash sequence”. From this definition, it was determined that the FEA models must primarily provide an assessment on the crashworthiness of the aircraft in terms of the structural integrity of the airframe to ensure a minimum safe occupant volume and the tolerance of humans to abrupt (de)accelerations. An assessment of other crashworthiness factors have been ignored in this study, such as post-crash hazards (e.g. fire) and safe egress for the occupants. Stockwell [2] performed a dynamic crash analysis of an all-composite Lear Fan aircraft impacting into concrete with the explicit nonlinear dynamic finite element code MSC Dytran. The structural response of components was qualitatively verified by comparison to experimental data such as video and still camera images. The composite fuselage materials were represented with the use of simplified isotropic elastic-plastic material models, and therefore did not account for the anisotropic properties of composite materials and the associated failure mechanisms. The occupants were represented as lumped masses; therefore occupant response could not be investigated. Malis and Splichal [3] performed a dynamic crash analysis of a composite glider impacting into a rigid surface with MSC Dytran; however further model verification was required. The 50th percentile adult male (occupant of average height and mass) Hybrid III anthropomorphic test device (ATD), also referred to as a crash test dummy, was represented in the analyses with the Articulated Total Body (ATB) model integrated within MSC Dytran. Various injury criteria of the ATB model were evaluated to determine the crashworthiness of the glider. Bossak and Kaczkowski [4] performed global dynamic crash analyses of a composite light aircraft crash landing. Representative wet soil, concrete and rigid impact terrains were modelled using Lagrangian-based finite element techniques and only the vertical velocity component of the aircraft was considered to simplify analyses. It was assumed that the previous use of only a downward vertical velocity component was a result of possible numerical instabilities which commonly occur with the use of Lagrangian solvers when considering problems with large deformations, which is a characteristic of crash analyses (i.e. the addition of a horizontal velocity component may result in severe element deformation of the soft soil terrain, resulting in premature analysis termination). Analyses of the occupant were performed in separate local models, using accelerations derived from the global analyses results. The real-time interactions between the occupant and aircraft therefore could not be investigated, which is considered a major disadvantage. Impact analyses of helicopters into water were performed by Clarke and Shen [5], and Wittlin et al. [6]. Both these papers showed promising results with the use of Eulerian-based finite element techniques to model the water. Additionally, combined horizontal and forward velocity components were assigned to the fuselages with success. It must be noted that the fuselages were modelled as rigid bodies; therefore the effect of structural failure on analyses could not be investigated. Fasanella et al. [7] performed drop tests of a composite energy absorbing fuselage section into water using Eulerian, Arbitrary Lagrange Eulerian (ALE) and Smooth Particle Hydrodynamics (SPH) meshless Lagrangian-based finite element techniques to represent water. Successful correlation between experimental and numerical data was achieved; however, structural failure could not be modelled with the Eulerian-based finite element technique due to analysis code limitations at the time. A “building block” approach was used in this study to develop accurate numerical modelling techniques prior to the implementation of the full-scale crash analyses. Once the blocks produced satisfactory results in themselves, they were then integrated in order to achieve the abovementioned primary aim of this study. The sub-components (or blocks) were the occupant (viz, FEA of the human bodies’ response to impact), (FEA of) soft soil impact and (FEA of) fibre-reinforced plastic composite structures. This approach is intuitive and provides key understanding of how each sub-component contributes to the full-scale crash analyses. Published literature was reviewed, where possible, as a basis for the development and validation of the techniques employed for each sub-component. The technique required to examine the dynamic response of an occupant with MSC Dytran, integrated with the ATB model, was demonstrated through the analysis of a sled test. The numerical results were found to be comparable to experimental results found in the literature. An Eulerian-based finite element technique was implemented for soft soil impact analyses, and its effectiveness was determined through correlation of experimental penetrometer drop test results found in the literature. An investigation into the performance of the Tsai-Wu failure criterion to capture the onset and progression of failure through the layers of fibre reinforced composite laminates was conducted for an impulsively loaded unidirectional laminate strip model. Based on the results obtained, the techniques implemented for each sub-component were deemed valid for crashworthiness applications (viz. to achieve the project aim). Full-scale crash analyses of impacts into rigid and soft soil terrains with varying aircraft impact and pitch angles were investigated. Typical limitations encountered in previously published works were overcome with the techniques presented in this study. The aircrafts’ laminate layup schedule was explicitly defined in MSC Dytran, thereby eliminating the inherent inaccuracies of using isotropic models to approximate laminated composite materials. The aircraft was assigned both horizontal and vertical velocity components instead of only a vertical component, which increased the model accuracy. Numerical instabilities, due to element distortion of the terrain when using a Lagrangian approach, were eliminated with the use of an Eulerian soft soil model (Eulerian techniques are typically used to model fluids where large deformations occur, which is a characteristic of crash analyses). Structural failure was successfully implemented by coupling Lagrangian and Eulerian solvers. The ATB model allowed for the real-time interactions between the occupant and aircraft to be investigated, unlike previously where analyses of the occupant were performed in separate local models using accelerations derived from the global analyses results. The results obtained from the crash analyses provide an indication of the forces transmitted to the occupant through the seat and restraint system, and the aircraft’s ability to provide a survivable volume throughout the crash event. The explicit nonlinear dynamic finite element based methodology was successfully implemented for investigating the crashworthiness of small lightweight composite aircraft, satisfying the primary aim of this study. Chapter 1 provides a review of fibre reinforced composite materials, the finite element method (FEM), ATDs and associated analysis codes, human tolerance limits to abrupt (de)accelerations, and crash dynamics and environment. The review of the FEM initially focuses on the fundamentals of FEA and then on the features specific to MSC Dytran as it is used throughout this study. Chapter 2 discusses the development of suitable numerical modelling techniques at the sub-component level and the implementation of these techniques within the full-scale crash analyses. Chapter 3 presents and discusses the full-scale crash analyses results for three impacts into rigid terrain and three impacts into soft soil terrain with varying aircraft pitch and impact angles. The results obtained from the crash analyses provide an indication of the forces transmitted to the occupant through the seat and restraint system, and the aircraft’s ability to provide a survivable volume throughout the crash event. Chapter 4 provides a conclusion of the work performed in this study and highlights various areas for future work. / D

This master’s thesis is dedicated to Side Impact Crash Tests Measurement in company Skoda Auto a.s.. Thesis describes measuring chain devices of Crash Test Laboratory, and also transferring and assessment process of crash record. Main part of Thesis describes eligible acceleration transducer attachment to B-Pillar of a vehicle.