bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Possible Role of Fluid/Solid Interactions in Minor Cervical Spine Injuries
Authors: Niederer Peter F. , Schmitt Kai-Uwe , Muser Markus H. , Walz Felix H. 
Published: November 2021

Abstract
Minor soft tissue injuries of the cervical spine pose increasing problems in public health. Such injuries are conveyed particularly often in rear-end automobile collisions at low impact speeds and it has been established that they may be associated with long-term impairment Among the hypotheses put forward in order to explain the occurrence of potentially harmful neck injuries at loading levels whose severity is generally considered well below tolerance limits which hitherto have assumed to be valid, interactions between fluid and solid structures have been postulated as injury mechanism. As the solid structures of the human body, i.e., skeleton, muscles, etc., are being accelerated and deformed through the action of impact forces, the fluids contained therein (blood, cerebrospinal fluid, interstitial fluids) are gradually dragged along or displaced because of viscosity or pressure gradients which are built up in the deforming solids. Ensuing relative motions and changes of fluid volumes cause viscous shear stresses and pressure peaks which may have an adverse influence, e.g., on cellular membranes. This hypothesis is supported by a number of experimental findings.
In this communication, mathematical modeling approaches are presented which are aimed at a quantification of fluid/solid interactions under loading conditions which approximate the impact situations of interest here. For this purpose, idealized fluid and solid systems are first considered which are exposed to a constant acceleration. The geometries are chosen such that analytic solutions can be obtained. Second, a detailed neck model is presented which includes vertebrae, discs, muscles, tendons as well as a representative fluid space (plexus venosus). The models are subjected to boundary conditions which correspond to typical low-speed rear-end impacts. It is found, that the level of shear stresses caused by fluids and acting on surfaces in fluid-filled bodies depends essentially on the size of the fluid spaces under consideration. Accelerations thereby exhibit a stronger influence than the duration during which they act. It cannot be excluded that critical levels are reached even in a low speed impact scenario. Calculated pressure peaks, in turn, remain within physiological limits.
Frontal Offset Crash: Smart Structure Solution
Authors: Jawad Saad A. , Baccouche Mohamed Ridha 
Published: November 2021

Abstract
The majority of real world frontal collisions involve partial overlap of the vehicle front. Excessive, intrusion is usually generated on the impacted side subjecting occupants to higher contact injury risk compared with full frontal collision. The problem encountered by the front end design engineer is to address conflicting requirements of keeping the G-level in the full frontal crash within its permitted values, and minimizing intrusions in offset crash. Traditional solutions to this problem focus on the use of three forked and cross members to ensure continuity of the load path into the passenger compartment. The ideal structure for offset crash is to stiffen the impacted side of the structure, and transfer part of the load to the non-impacted side to even out the load on both sides. Smart hydraulic structure is proposed to meet these ideal requirements. Sample hydraulic “Smart Structures” were designed and tested for feasibility of crash under high-pressure and high-speed impact conditions.
This research is attempting to find a solution to the design trade off faced by the designer for offset crash. A novel system of “Smart Structures” is introduced to support the function of the existing passive structure. The proposed “Smart Structures” consist of two independently controlled hydraulic cylinders integrated with the front-end rails.
A ten-degrees of freedom, two-dimensional spring-mass-damper simulation model has been developed to study the dynamics of crash between two vehicles in head-on collisions. The model inputs mass, speed of both colliding vehicles, overlap ratio and deformation characteristics of both passive and “smart” structures. The model assumes that the two colliding structures geometrically interact with each other. Full simulations of various scenarios of offset crashes were investigated using “Smart Structures” integrated with the front rail members.
Deployable “Smart Structures” have not been considered in this paper as this scenario was covered in previous publication (9). “Smart Structures” proved superior to the traditional passive structures by absorbing more energy for the same crush zone distance, stiffening the impacted side and stiffening the structure at high-speed impacts. The results are reduced intrusion for offset crashes while maintaining the permitted G-level in both full and offset crashes.
Crush Characteristics of E-Glass Tubes in Off-Angle Impacts
Authors: Mahmood Hikmat F. , Loosle David G. , Moosa Adil G. 
Published: November 2021

Abstract
Off-angle impact behavior and specific energy absorption (SEA) of E-glass/polyurethane square tubes have been investigated under static and dynamic loading. Various fiber orientations, braided, CSM (Continuous Strand Mats), and RCM (Random Chopped Mats) lay-ups were used. Consistent test data suggested that dynamic off-angle crush forces are lower than the static ones. Dynamic maximum moments during a progressive crush are slightly higher than its static counterpart. Tubes constructed of CSM and RCM break-off when the maximum moment is reached whereas, tubes constructed of stitched/braided fiber fold upon reaching the maximum moment and remain intact. Specific energy absorption is reduced with the increase of impact angle due to combined loading effect. Certain lay-ups give more SEA than others. Ratios of average static to dynamic crush force are presented for different lay-ups and impact angles.
Development of Undergraduate Mechatronics Course in the School of Mechanical Engineering at Georgia Tech
Authors: Ume I. Charles , Kita Akio 
Published: November 2021

Abstract
As the field and applications of Mechatronics grow, engineering education must grow with it to meet the changing needs of students and industry. How to teach Mechatronics continues to be an open area for discussion. The subject is interdisciplinary and it is continuously changing. This presentation focuses on the structure and growth of the undergraduate Mechatronics courses in the Woodruff School of Mechanical Engineering at Georgia Tech. The goal is to provide students with a fun, hands-on, challenging, project based and collaborative learning approach to mechatronics education. An overview of the course and the laboratory experiences is presented. Student projects are included to highlight the topics tackled in the course.
Capstine Design Projects for Mechatronic Design in Mechanical Engineering Department
Authors: Erden Abdülkadir 
Published: November 2021

Abstract
The current paper describes the minor program in mechatronics engineering developed at the Middle East Technical University. The paper gives the main structure of the program with a discussion on the design of the new courses in mechatronics. Sample project topics are also given for the mechatronics design courses. Emphasis is placed on the design features of the mechatronics courses.
Failure Analysis and Redesign of a Pressure Powered Pump Mechanism
Authors: Brader John S. , Rocheleau David N. 
Published: November 2021

Abstract
This paper identifies the field failures of a Pressured Powered Pump (PPP) mechanism and presents the analysis and subsequent corrective action taken to prevent these failures. The Pressure Powered Pump is a mechanism that converts the liquid level within the body of the pump to the position and actuation of two valves on top of the pump. The two valves control motive pressure within the pump, and therefore, control the pumping action. Tracking in-use field data, it was seen that the pump fails at several locations, which, regardless of the location of the failure, can be attributed to an ill-designed crank-slide mechanism inside the pump. The purpose of the project, and thus the subject of this paper, is the analysis of these failures, the identification of the typical mode of failure, and the subsequent corrective action taken to prevent these types of failures.
The PPP project was executed at the University of South Carolina with support from the manufacturer of the pump. To identify and prevent failures of the pump, three phases were undertaken. First, a failure analysis of the existing mechanism and failed components was performed. Second, using the analysis information, a redesign of the pump was undertaken. And third, a new analysis was performed on the redesigned mechanism, which turned out to be a slider crank. The outcome of this work is a pump whose mechanism now operates under reduced forces and stresses; thus, results in a pump with a predictably longer lifecycle and far fewer failures.
Failure Analysis and Redesign of Some Import Motor-Driven Devices of Valve
Authors: Zhang Jiancheng , Zhou Entao , Zhou Shichang , Li Guodong , Liu Pengjie 
Published: November 2021

Abstract
Combining with the failure analysis of a class of import motor-driven devices of valve and the design of new kinds, several problems worth noticing in the design of motor-driven devices of valve have been discussed. These are the failure analysis and the redesign of changeover mechanism between manual operating and motor driving, the redesign of the setting way for valve opening, the reform of the measurement of transmission way for valve opening, and the selections of the parameters about velocity and force of the device. Based on these analyses, redesigned motor-driven devices of valve have been successfully applied in industry. The conclusions obtained have certain referential values to related research.
Failure Analysis of the Rear Axles in a Sports Utility Vehicle (SUV)
Authors: Rasty Jahan , Le Xiaobin 
Published: November 2021

Abstract
In a rollover accident, both rear axles of a Sports Utility Vehicle (SUV) were fractured adjacent to the wheel-mounting flange. The purpose of this paper is to describe the methodology and experimental techniques used in determining whether one or both axles failed prior to the accident, and thus contributing to the accident, or whether both axles failed as a result of the rollover and the ensuing impact with the highway. Scanning Electron Microscopy (SEM) technique was used to obtain detailed characteristics of the fracture surface on both axles. Through-thickness hardness profile of the axles was determined using incremental micro-hardness measurements in order to assess the depth of case hardening in both axles. Impact, tensile and fatigue specimens were machined from the remaining parts of the failed axles and were tested to destruction using standard impact (Izod), tensile and fatigue tests. The fracture surface characteristics of the test specimens were compared to those of the failed axles in order to isolate the mode of failure. Based on the results of the above tests, the history of the repair work performed on the rear wheel bearings and the physical evidence of various marks and damages remaining on the vehicle’s body, it was determined that one of the rear axles failed prior to the rollover, while the other occurred as a result of the rollover and ensuing impact with the highway.
Three-Dimensional Analysis of Double Rivet-Row Lap Joints: Part II — Countersunk Rivets
Authors: Iyer K. , Rubin C. A. , Hahn G. T. 
Published: November 2021

Abstract
Three-dimensional finite element analysis of an elastic, double rivet-row, aluminum alloy lap joint with countersunk, aluminum and steel rivets, is presented. Relations between the connection compliance, rivet deformation, peak contact pressures and slip amplitudes, in the absence of interference and clamp-up, are described. Analysis of a connection with non-countersunk rivets is presented in a companion paper. The trends seen in the results are similar to those obtained with non-countersunk rivets, although the peak stress concentrations in the present case are much higher. A superposition approach for estimating stress concentration factors in the panels of multi-row riveted connections with standard or countersunk rivets is presented.
Multiaxial Impact Behavior and Modeling of ABS Polymer
Authors: Saigal A. , Greif R. , Duan Y. , Zimmerman M. A. 
Published: November 2021

Abstract
The multiaxial impact behavior of CYCOLAC GPM5500 (ABS glassy polymer) is obtained as a function of impact velocity and temperature from the standard impact test as specified by ASTM D3763. Finite element analysis (FEA) and ABAQUS/Explicit are used to model the impact behavior of the polymer. The generalized “DSGZ” constitutive model, previously developed by the authors and calibrated using low strain rate uniaxial mechanical test data, is extended to the high strain rate regime and used in the finite element analysis. Load-displacement curves from the finite element analysis are compared with the experimental data and agree well up to the maximum impact load (failure). Therefore, the proposed finite element analysis model can be used to predict the multiaxial impact behaviors of polymers at different temperatures and impact velocities.
Mixed Mode Interfacial Fracture Toughness Evaluation for Flip-Chip Assemblies and CSP Based on Fracture Mechanics Approaches
Authors: Auersperg Jürgen , Kieselstein Eva , Schubert Andreas , Michel Bernd 
Published: November 2021

Abstract
The increasing use of advanced electronic packages like Flip Chips and CSP under harsh environmental conditions, extreme temperatures is often a reason for damage, fatigue and failure of entire components and systems. Consequently, their thermo-mechanical reliability is one of the most important preconditions for adopting these technologies in industrial applications. To prevent chips from being exposed to the external environment integrated circuits are usually encapsulated into packages. As a result, a microelectronic package is basically a compound of several materials with quite different Young’s moduli and thermal expansion coefficients. Additionally, various kinds of inhomogeneity, residual stresses from several steps of the manufacturing process contribute to interface delaminations, chip cracking and fatigue of solder interconnects. This paper intends to describe the investigation of damage and interface delamination phenomena in micro components by numerical investigations by means of fracture mechanics concepts based on nonlinear FEA and experimental investigations. Consequently, the contribution shows the use of non-linear finite element simulations with respect to the nonlinear, temperature and rate dependent behavior of different materials used, the application of fracture mechanics concepts (energy release rate, integral fracture approaches, mode-mixity examinations) in combination with experimental investigations. For these purpose, bending specimens consisting of several materials interfaces widely used in FC ssemblies and CSP have been investigated in particular. In order to evaluate the different approaches used some results have been compared to micrographs from growing interface delaminations by using micro deformation measurements on the basis of a gray scale correlation method applied to micrographs, in particular. The methodology explained is a helpful basis for understanding and evaluating failure mechanisms especially of several polymer material interfaces as well as of solder joints in a more consistent manner. It should support further applications for raising the thermo-mechanical reliability of advanced electronic packages.
Design of a Mortar-Deployed Video Imager
Authors: Condon John A. 
Published: November 2021

Abstract
As part of a US Army Research Laboratory (Aberdeen Proving Ground, MD) project to provide electromechanical packaging support for a developmental gun-hardened, munition-deployed, parachute-deployed video imager, a dynamic FEA structural analysis was performed on the imager’s aluminum housing. This imager can provide real-time, telemetered, digitally-encrypted and encoded video imaging of the battlefield. The housing was designed as a carrier for the power distribution electronics; video encoding electronics; telemetry transmitter and wrap-around antenna; rechargeable NiCad batteries; and CCD camera module, and provided for direct replacement of an existing illumination canister within a modified US Army 120mm mortar system. The imager assembly, once inserted within the mortar body, is first exposed to a launch ‘setback’ acceleration load upon firing and then is exposed to an explosively-generated internal pressure and impact loading upon in-flight fuze initiation, mortar body separation and subsequent imager submunition expulsion. The dynamic analysis entailed verification of the structural integrity and deflections of the imager housing and adjacent impacting steel ‘pusher’ plate under launching, pressure, and impact loadings. A 2-D axi-symmetric, quadrilateral-only, finite element model of the housing and pusher plate was constructed. Contact elements, birth & death displacement constraints and simplified mortar body elements were added to simulate the boundary conditions. Analysis predictions were validated by inspection of the recovered imager hardware following flight testing.
Design of a Human Powered Moonbuggy
Authors: Goforth Emily Kinnaird 
Published: November 2021

Abstract
NASA hosts an annual competition called The Great Moonbuggy Race at Marshall Space Flight Center in Huntsville, Alabama. In the Spring of 2001, the Mechanical Engineering Senior Design Class was divided into three teams and requested to design and build a device for competition. The design criterion was to build a human-powered device capable of carrying one male and one female student across a half mile of simulated lunar terrain. Time was a key criterion as entries were timed on their speed of assembly as well as speed through the course. Other important criteria included safety of the drivers, un-assembled dimensions, inclusion of simulated equipment that an actual moonbuggy would need, and maximum turning radius. The cost of the project had to be within a specified budget of $750. Our moonbuggy, which was constructed under the given budget, survived both runs on the course without any damage. We finished in the top ten of the competition.
Nano-Micro Scale Characterization of Dielectric Materials
Authors: Kohl Paul A. , Allen Sue Ann Bidstrup 
Published: November 2021

Abstract
Thin films of dielectric materials are used as insulating layers in microelectronic systems, including integrated circuits and printed circuit boards. Polymer and spin-on-glasses are widely used as coatings and interlevel dielectrics. The dielectric permitivity and loss are the electrical properties of most interest. However, characterization and optimization of the mechanical properties is essential to the successful implementation and usage of these insulators. In this presentation, thin-film structures for measuring direction-dependent properties (dielectric constant, elastic modulus, and coefficient of thermal expansion), and nano-indentation results on spin-on-glass materials will be presented. Significant improvement in the fracture toughness of nanoporous methylsilsesquioxane glass films has been demonstrated upon introduction of porosity into the films.
Mechanics Issues at Micro-Scale Modeling of Electronic Packages
Authors: Pucha Raghuram V. , Ramakrishna Gnyaneshwar , Sitaraman Suresh K. 
Published: November 2021

Abstract
Due to the temperature dependent material properties and low cycle thermo-mechanical fatigue of electronic packaging interconnects and components, plasticity theories are extensively used to understand their mechanical response in estimating the fatigue life. Experimental evidence indicates that plastic deformation at small scales depends not only on the state variables of stress and strain, but also on their higher order gradients. In this paper mechanics issues related to strain gradient plasticity at micron scale are reviewed through strain gradient enhanced continuum theories. A plastic strain gradient-based approach is employed to study the thermo-mechanical deformation of microvia structure.
Computational and Experimental Study of Laser Microwelding Processes for Electronic Packaging
Authors: Han Wei , Pryputniewicz Ryszard J. 
Published: November 2021

Abstract
Advances in microelectronics depend on reliable packaging. As sizes of components decrease and number of components per package increases, demands on interconnections, or joining, of two parts, e.g., wire to tab, or tab to tab, increase rapidly. Since traditional joining techniques, such as resistance welding, may no longer produce satisfactory microinterconnections, alternative methods are being developed. One of such methods is based on laser microwelding. In this paper, we discuss fundamental processes involved in laser microwelding, outline a computational methodology to simulate thermal effects produced, describe facilities used, present results, and summarize correlations between the experimental and computational data for applications in electronic packaging.
Failure Analysis of Miniature Solder Specimen
Authors: Wei Y. , Chow C. L. , Fang H. E. , Neilsen M. K. , Lim T. J. , Lu W. 
Published: November 2021

Abstract
The effects of specimen geometry size on the behavior of 63Sn-37Pb solder are investigated both experimentally in the laboratory and analytically with finite-element simulations. The simulations are achieved by developing a constitutive model for solder which couples viscoplasticity with a unified damage theory. The unified damage theory is characterized by a damage surface in strain space which separates fatigue damage from inelastic damage. The damage evolution equations are derived within the framework of irreversible thermodynamics. A series of uniaxial tension, tensile creep, and strain-controlled fatigue experiments are performed to obtain material parameters for the solder damage model. The solder damage model is then implemented into a finite element code and used to simulate a uniaxial tension test on a miniature specimen and on a standard ASTM specimen (ASTM standards, 1999). Predictions from these simulations are then compared with each other and with experimental results in order to examine specimen size effects.
High Digital Speed Level-2 Interconnections via a New Microcontact Design
Authors: Pryputniewicz Dariusz R. , Grabbe Dimitry G. , Pryputniewicz Ryszard J. 
Published: November 2021

Abstract
Requirements for high digital speed, high density, level-2 interconnections have led to development of a new microcontact. Design of this microcontact allows for separable and reusable interconnections. In this paper, we discuss methodology used to develop the microcontact, allowing 100% material utilization, present its design, including analysis and process optimization, and summarize its characteristics as they relate to electronic packaging.