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>

Flight and drop tests of the Martin 270 (M270) seaplane were conducted in 1955. Theoretical and empirical pressures were determined by use of Wagner’s theory and also by the Code of Federal Regulations (CFR). The pressure results from the experimental tests on the hull were compared with pressures calculated from Wagner’s theory to determine how well the theory correlated with the measured pressures. The experimental pressure data was also compared with the CFR results to determine how the current industry standard of estimating impact loads compares with actual pressures a seaplane is subjected to. Using the structural design and geometry of the M270 the seaplane hull was modeled in Maestro with a coarse mesh finite element model. The pressures from Wagner’s theory and the CFR were applied to the model of the M270 hull. The structural reactions of the drop test section were compared with the reactions determined from Maestro.

<p><!-- @page { size: 8.5in 11in; margin: 0.79in } P { margin-bottom: 0.08in } --></p><p>Free fall drop testing is an important part of the development of commercial electronic components and devices. In the process of optimizing the quality of their entire product range, Sony Ericsson Mobile Communications AB have decided to review their free fall drop test equipment with the goal of increasing the precision, repeatability, and time efficiency of their drop test applications. In regard to the free fall drop test principle a robot system with management software, named Doris Drop Test System, is developed to meet these goals.</p><p>As the amount of related work for this application is as minimal as the timeframes for this project, the development process is empirical and entrepreneurial with engineering skills as the governing line of work. Combining the competence from fields such as mechanics, electronics and product development, reaching the goals is successful enabling the identifying of two different drop methods – Impact Position and Drop Position. Increasing the repeatability from approximately 10% to 85% enables anyone at any time to perform the exact mobile phone drop test. By reaching a precision of up to 100%, performing free fall drop tests aiming for testing specific mobile phone parts, optimizes the development process by faster detection of mechanical weaknesses. Achieving these results in parallel with increasing the throughput by shortening the testing time, has proven the success of the Doris Drop Test System.</p><p> </p>

The Wafer Level Chip Scale Package (WLCSP) is gaining popularity for its performance and ability to meet the miniaturization requirements of portable consumer electronics, such as cell phones. For the industry of electronic package, the package life of electronic products is deemed as the essential consideration in the operation period. In practice, electronic products are usually damaged due to a harsh mechanical impact, such as drop and bending. The solder interconnections provide not only the electronic path between electric components and printing circuit board, but also the mechanical support of components on the printing circuit board, so that the reliability of solder interconnection becomes an essential consideration for a package. In the thesis several parameters, including redistribution layer (RDL) material and thickness, passivation material and thickness, under-bump metallization (UBM) structure factors are discussed. A variety of WLCSP structures are investigated for solder joint reliability performance. In addition to the fatigue lives of the test vehicle, locations and modes of fractured solder joints were observed. It was found that wafer level packaging structure under drop clearly related with the characteristic life. The weakest point of solder ball was intermetallic compound (IMC), and wafer level packaging structure was the crack into the second passivation layer and UBM interface of the corner. WLCSP under temperature cycling test was done and observed the fracture only occurred at the solder ball near the package.

Ion contaminants from Printed Circuit Board (PCB) assembly processes pose a high reliability risk because they result in damaged circuits. Therefore, it is essential to understand the level of ionic species on the electronic circuitry as well as the reliability risks caused by these contaminants. There are a number of approaches available in the industry to assess the reliability risks ; for example, the water drop test (WDT) is one of the techniques used to determine the propensity of an ionic contaminant to cause electrical short failures by dendrite formation. The objective of this research is to determine the time to cause the failures, known as electrochemical migration (ECM) failures. A test vehicle was developed for the WDT to obtain the time to cause ECM failure in presence of different anions. The time to form dendritic bridges that cause short circuits was determined as a function of the different anions and the spacings between PCB pads. The experimental method involved dispensing aqueous solutions containing common inorganic and organic acid anions onto test vehicles, applying electrical bias voltages and measuring the time to form dendrites. Specially designed test structures cells were created to contain the test solutions. At each of the test cells, a cavity held the solution and constant current was applied through different metal geometries. To be representative of popular board finishes, test vehicle boards incorporated both Sn-Pb Hot Air Soldering Level (HASL) and Pb free HASL surface finishes.

<!-- @page { size: 8.5in 11in; margin: 0.79in } P { margin-bottom: 0.08in } --> Free fall drop testing is an important part of the development of commercial electronic components and devices. In the process of optimizing the quality of their entire product range, Sony Ericsson Mobile Communications AB have decided to review their free fall drop test equipment with the goal of increasing the precision, repeatability, and time efficiency of their drop test applications. In regard to the free fall drop test principle a robot system with management software, named Doris Drop Test System, is developed to meet these goals. As the amount of related work for this application is as minimal as the timeframes for this project, the development process is empirical and entrepreneurial with engineering skills as the governing line of work. Combining the competence from fields such as mechanics, electronics and product development, reaching the goals is successful enabling the identifying of two different drop methods – Impact Position and Drop Position. Increasing the repeatability from approximately 10% to 85% enables anyone at any time to perform the exact mobile phone drop test. By reaching a precision of up to 100%, performing free fall drop tests aiming for testing specific mobile phone parts, optimizes the development process by faster detection of mechanical weaknesses. Achieving these results in parallel with increasing the throughput by shortening the testing time, has proven the success of the Doris Drop Test System.

Computer simulation is an essential tool in the development process of childseats, particularly when it comes to ensuring the safety of child passengers.As awareness regarding child passenger safety continues to grow, the use ofsuitable materials in the development of child seats becomes increasinglycrucial. Numerical simulations play a vital role throughout the entiredevelopment phase, enabling accurate analysis and evaluation. Toeffectively reduce development costs and time, it is imperative to have amaterial model that accurately predicts the behavior of materials innumerical simulations. This enables optimized performance of child seatswhile maintaining safety standards. The objective of the thesis is to implement a standard procedure forextracting material data for numerical modelling of foam materials andvalidating it. In this study, material models available in LS-DYNA, such asMAT_083 and MAT_057 for foam materials, are utilized along withcompression test data to create the material model. The model is furtherenhanced by optimizing the material parameters to establish a correlationbetween the test and simulation results. The improved material model is thenvalidated by comparing it with the impact drop test results. However,THULE's current impact drop test equipment is not considered accurate orefficient, and addressing this issue is one of the main objectives of thisthesis. Within this thesis, the identified problems are thoroughly examined,and suitable solutions are proposed to ensure the accurate extraction ofmaterial data and its validation, particularly when introducing new foammaterials.

Quando ocorre uma colisão, o comportamento estrutural de veículos, componentes ou sistemas mecânicos é analisado através de um parâmetro chamado crashworthiness, conceituado como a capacidade ou habilidade de uma estrutura, ou parte dela, de absorver energia cinética (resultante de impacto) e manter o colapso sob controle, mantendo a integridade no espaço do(s) ocupante(s). Este parâmetro pode também ser determinado para outro tipo de estruturas, como por exemplo, dispositivos de armazenamento de material (containers). Esta dissertação apresenta uma revisão bibliográfica sobre crashworthiness e o comportamento de estruturas quando submetidas a ensaios de impacto. Apresentam-se conceitos, histórico, evolução e principais áreas envolvidas. Destaca-se a utilização de programas de modelamento por elementos finitos na simulação e análise de colisão. Simula-se e analisa-se o impacto de modelos simplificados de container, típicos para o armazenamento de material radioativo, em queda livre contra uma superfície rígida, utilizando o software de elementos finitos ANSYS/LS-DYNA numa análise dinâmica explícita, apresentando-se resultados e conclusões e sugestões para trabalhos futuros. / The structural behavior of a vehicle or a mechanical system during collision is a very complex event. To analyze this behavior it's necessary to submit them to crash tests. These tests are made for the determination of the structure behavior and measure the kinetic energy absorption capability of a structure produced during a collision. This parameter is known as crashworthiness. In this work it is made a bibliographical review about crashworthiness and the behavior of structures under impact tests. Also, concepts, historical, evolution and the main involved areas are presented. The use of software's of finite elements in modeling and analyze of impact tests its highlighted. The drop test of a model of container, typical to storage of radioactive waste, is performed using the software of finite element ANSYS/LS-DYNA in an explicit analysis. Results, conclusions and comments for futures works are presented.

Quando ocorre uma colisão, o comportamento estrutural de veículos, componentes ou sistemas mecânicos é analisado através de um parâmetro chamado crashworthiness, conceituado como a capacidade ou habilidade de uma estrutura, ou parte dela, de absorver energia cinética (resultante de impacto) e manter o colapso sob controle, mantendo a integridade no espaço do(s) ocupante(s). Este parâmetro pode também ser determinado para outro tipo de estruturas, como por exemplo, dispositivos de armazenamento de material (containers). Esta dissertação apresenta uma revisão bibliográfica sobre crashworthiness e o comportamento de estruturas quando submetidas a ensaios de impacto. Apresentam-se conceitos, histórico, evolução e principais áreas envolvidas. Destaca-se a utilização de programas de modelamento por elementos finitos na simulação e análise de colisão. Simula-se e analisa-se o impacto de modelos simplificados de container, típicos para o armazenamento de material radioativo, em queda livre contra uma superfície rígida, utilizando o software de elementos finitos ANSYS/LS-DYNA numa análise dinâmica explícita, apresentando-se resultados e conclusões e sugestões para trabalhos futuros. / The structural behavior of a vehicle or a mechanical system during collision is a very complex event. To analyze this behavior it's necessary to submit them to crash tests. These tests are made for the determination of the structure behavior and measure the kinetic energy absorption capability of a structure produced during a collision. This parameter is known as crashworthiness. In this work it is made a bibliographical review about crashworthiness and the behavior of structures under impact tests. Also, concepts, historical, evolution and the main involved areas are presented. The use of software's of finite elements in modeling and analyze of impact tests its highlighted. The drop test of a model of container, typical to storage of radioactive waste, is performed using the software of finite element ANSYS/LS-DYNA in an explicit analysis. Results, conclusions and comments for futures works are presented.