Petru A. Simionescu

Petru A. Simionescu
Texas A&M University - Corpus Christi · School of Engineering and Computing Sciences

About

92
Publications
72,804
Reads
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647
Citations
Citations since 2017
31 Research Items
279 Citations
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201720182019202020212022202301020304050
201720182019202020212022202301020304050
201720182019202020212022202301020304050
Additional affiliations
January 2010 - present
Texas A&M University - Corpus Christi
Position
  • Professor (Associate)

Publications

Publications (92)
Book
Full-text available
This book presents the reader with theoretical concepts, practice problems and project ideas on planar linkage mechanism kinematics, motors and actuators, loads in machines and mechanisms, balancing, flywheel design, cam-follower mechanisms, single and multi-speed transmissions, involute gears, reciprocating engine dynamics, vibration analysis, cri...
Cover Page
Full-text available
Visit www.inderscience.com/ijspr for more information and sample articles of the International Journal of Student Project Reporting
Chapter
The synthesis of planar four-bar-linkage for two and three prescribed positions of the input and output links is classical to mechanism design. A revisit of this problem using equations of constraints is presented in this paper. Optimization problems are then formulated where best transmission angles (with or without link-length constraints) are ad...
Chapter
Steering is an essential function of any vehicle, manned or unmanned. Modern wheeled vehicles employ steering systems perfected in the last 250 years. In this paper, the most common steering linkages and steering boxes are inventoried, and an attempt is made to identify the main contributors to their development. For example, the trapezoid steering...
Book
Full-text available
This Compendium includes over 850 figures and diagrams of applied mechanisms and machines, accompanied by online resources with videos and simulations (www.youtube.com/MechCompendium). The last chapter lists 143 eponyms compiled as a tribute to their originators, and to their contribution to Mechanism and Machine Science. This Compendium should be...
Preprint
Full-text available
In this paper, a semester-long project for an undergraduate mechanical-systems-design course is presented. The project requires students to perform kinematic and load torque analysis of a crank-driven punch press, choose a suitable electric motor, and calculate the moment of inertia of the flywheel such that an imposed coefficient of speed fluctuat...
Conference Paper
Full-text available
Simulations of several linearly, radially, and circularly deployable structures and mechanisms of the scissor type has been performed using the MeKin2D package. By calling modular-kinematics subroutines within do while loops, complex planar repeatable mechanisms can be simulated easily, and their workspace and other properties assessed.
Article
Full-text available
Covering with plastic film in fall and planting through the film in spring is an effective drought-resistance, potato-cultivation method. To achieve proper under-plastic-film, hill-drop potato seeding, the geometry of an existing five-link planter mechanism that is driven synchronously by two cranks rotating in the same direction has been refined t...
Article
Full-text available
The paper presents a general approach to the steady-state efficiency analysis of one degree of freedom (1-DOF) speed increasers with one or two inputs, and one or two outputs, applicable to wind, hydro and marine-current power generating systems. The mechanical power flow, and the efficiency of this type of complex speed increasers, are important i...
Article
Full-text available
—The oscillating-slide linkage, symbolized RPRR is one of the most utilized inversions of the slider-crank mechanism. This paper considers the cases where the rocker of n RPRR mechanism is loaded primarily by gravitational forces, like in boom cranes, dump trucks and aerial-work platforms. In all these applications, in addition to satisfying impose...
Article
Full-text available
The new technology of filming in autumn and planting directly through the plastic film in spring is an effective water-saving method and drought-resistance commercial potato production. However, filming first and then planting is not compatible with the working of known potato mulching planters. In order to realize the hill-drop under plastic-film...
Chapter
The paper discusses the steady-state modeling of wind turbines with two counter-rotating wind rotors and counter-rotating electric generator, which additionally employs a two degrees of freedom planetary speed increaser with two inputs and two outputs. The model uses the kinematic and static functions of the speed increaser, the mechanical characte...
Chapter
Full-text available
Several Working Model 2D simulations for the analysis of disk-cam mechanisms and for cam profile generation as follower envelope in a motion inversion approach are presented. Using these simulations, the relationship between the follower motion program, follower bias and its geometry and cam undercut can be suggestively demonstrated. As shown in th...
Chapter
Full-text available
The paper describes the use of MATLAB software in the synthesis of cam mechanisms as follower envelopes, using motion data read from file. Disk cams with translating and oscillating followers, flat-faced, pointed and with roller are discussed, as well as wedge cams with roller-follower. Full MATLAB programs are provided, together with the descripti...
Article
Full-text available
Simulations of several repetitive mechanisms, some of them considered difficult to perform, have been done relatively easily using for loops and the MeKin2D modular-kinematics subroutines. These simulations include generation of multiple couple-curves, wicked-vane and aperture mechanisms, feathering paddlewheels, radial engines and a folding pop ri...
Article
Full-text available
Closed-form equations for the analyses of the RRR and RRT (passive), and of the RRRR and RRRT (active) kinematic building blocks are presented in the paper. Implementations of these equations in computer subroutine are then discussed. Applications chosen to illustrate the usefulness of these subroutines include: optimum-synthesis of a function gene...
Experiment Findings
Full-text available
Animated GIFs of four-bar and slider crank coupler cognates, stationary cylinder and Gnome radial engines, a tire curing press and Hoberman mechanism.
Chapter
Full-text available
Mechanism and Machine Science (MMS) contributed for thousands of years to our society with the discovery and invention of machines, machine elements and mechanisms. Many such contributions have been attributed to others rather than to their originators, while the authors of other notable contributions have been forgotten. In this paper it is propos...
Chapter
Full-text available
Twenty textbooks on Mechanism and Machine Theory (MMT) have been analyzed, revealing, for the most part, a reduced number of figures of practical machines and mechanisms. Also noted is a de-emphasis of MMT in engineering curricula, and reduced funding of Mechanical Engineering research, while industry-academia collaboration is hindered by bureaucra...
Chapter
Full-text available
To enhance their mechanical design and prototyping skills, engineering students at Texas A&M University Corpus Christi have built an off-road vehicle for the Basic Utility Vehicle (BUV) Competition. Some of the design details of the transmission, steering and braking system of this utility vehicle are presented in this paper, accompanied by compute...
Chapter
Full-text available
Kinematic simulations of a selection of linearly, radially and circularly deployable structures have been performed using the modular-kinematic sub-routines available from the MeKin2D package. By employing do-while loops, relatively simple, yet flexible simulation programs can be written, useful for workspace, maximum reach and other kinematic prop...
Conference Paper
Full-text available
The paper presents an example of Working Model 2D multibody software use in the reconstruction of a high-speed side-impact accident of two automobiles. The simulation (part of a contested judicial litigation) allowed to clarify whether at the time of the accident, the impacting vehicle was impermissibly passing to the left of the continuous center...
Patent
Full-text available
The present invention is concerned with an apparatus for simulating the chewing process for the purpose of testing dental materials and implants and for the purpose of analyzing food samples. The apparatus comprises a frame , a stationary platform connected compliantly to the said frame and a moving platform corresponding to the maxillae and mandib...
Patent
Full-text available
A vertical takeoff and landing unmanned aerial vehicle (VTOL-UAV) is provided consisting of one central motor which drives one ducted fan and one or more rotors. These rotors can be coaxial with the fan, or can be located off-center being driven via a transmission. For flight control purposes, all or a portion of the air circulated by the ducted fa...
Article
Full-text available
The oscillating-slide inversion of the slider-crank mechanism, commonly symbolized RPRR, is widely used to convert the displacement of an input linear motor (either electric, hydraulic or pneumatic), into the swing motion of a rocker. This paper discusses the optimum kinematic synthesis of the centric RPRR mechanisms for prescribed limit positions,...
Article
Full-text available
This paper presents a unified approach to the problem of dimensional synthesis of the five-link, four-link, and three-link (double-wishbone) suspension mechanisms with a rack-and-pinion steering input. In a simplified approach, the guiding links are assumed to be removed from their joints, allowing the wheel to be exactly driven through a number of...
Conference Paper
Full-text available
This paper presents the development, results and trainee perception of a laboratory experiment used for diagnosing the occurrence of different faults in impeller-pump induction motors by means of the Motor Current Signature Analysis (MCSA) technique. This is a quintessential experiment, relatively inexpensive and easy to implement, that combines el...
Conference Paper
Full-text available
MeKin2D is a collection of subroutines for kinematic simulation of planar linkages using a modular approach, for synthesis and analysis of disk-cam mechanisms with various types of followers, and for involute gear generation. The original set of subroutines accompanies as supplementary material a book by this same author released in 2014. These, as...
Conference Paper
A hyperspectral and thermal imaging system have been used to acquire hyperspectral data and thermal images from the surface of galvanized steel parts. After heating the parts in an oven, heat maps have been partitioned into hot (red) and cold (blue) regions as relative representation of heat distribution, to correlate the spectral signatures from h...
Research
Full-text available
Animated GIF files accompanying the paper "A Unified Approach to the Kinematic Synthesis of Five-link, Four-link and Double-wishbone Suspension Mechanisms with Rack-and-pinion Steering Control"
Presentation
Full-text available
Automobiles that are no longer roadworthy, and used automobile-components can be used to fabricate homemade tractors and off-road transport vehicles. Such conversions were practiced in the past by small farm owners in the USA, and could be adopted by nowadays Eastern European farmers and from other pars of the Developing World.
Article
Full-text available
The problem of optimum synthesising of a mechanism to best approximate a function, while simultaneously ensuring good motion transmission characteristics is discussed. Distinction is made between the design variables that determine the shape of the input-output (I/O) function of the mechanism, and the design variables that affect the degree of over...
Conference Paper
In this paper we present a comparative analysis of three vision systems to nondestructively predict defects on the surfaces of aluminum castings. A hyperspectral imaging system, a thermal imager, and a digital color camera have been used to inspect aluminum metal cast surfaces. Hyperspectral imaging provides both spectral and spatial information, a...
Article
Full-text available
Two formulations of the RPRPR-chain kinematics are discussed, one using equations of constraint, the other a vector loop approach. These are compared with respect to motion-transmission indicators, differences in plotting the kinematic chain when assembly is not possible, and CPU time required by one set of calculations. By locking one or both slid...
Book
Full-text available
This book allows readers to expand the versatility of AutoCAD® design and documentation software. It provides ready-to-use procedures and computer programs for solving problems in a variety of application areas, including computer-aided design, data visualization, evolutionary computation, numerical methods, single and multicriteria optimization, l...
Conference Paper
Full-text available
The paper discusses the design and prototype build of a sun tracking system for photovoltaic panels, that consists of a slider-rocker mechanism and a controls system. The slider-rocker is optimized for best transmission angle properties, near linear input-output function and 180 degrees rocker travel. The control system includes three shaded light-...
Conference Paper
Full-text available
The paper discusses the design and prototype build of a sun tracking system for photovoltaic panels, that consists of a slider-rocker mechanism and a controls system. The slider-rocker is optimized for best transmission angle properties, near linear input-output function and 180 degrees rocker travel. The control system includes three shaded light-...
Article
A comparative study of three imaging technologies has been conducted to nondestructively assess the thickness and strength of oyster shells grown in various environmental conditions. Oyster shell thickness and strength are expected to be dependent on the harshness of the oyster's environment as well as other factors. Oysters have been grown in envi...
Article
The paper presents a novel technique for the kinematic analysis of bevel gear trains using the incidence matrices of an edge-oriented graph of the mechanism. The kinematic equations are then obtained in matrix form using a cycle basis from a cycle matroid. These equations can be systematically generated, and allow for an efficient computation of th...
Article
Full-text available
The use of information visualization in engineering analysis and design has increased exponentially, making it indispensable in science and engineering education. In this paper, several new concepts on graphical representation of two-dimensional data are presented, and their implementation in a computer program called D_2D detailed. Application exa...
Article
Full-text available
Based on the problem of visualizing the potential energy of a two-degree-of-freedom spring-mass system restrained by an elastic string, several advancements to visualizing functions with constraints and inequalities of two variables are introduced. These innovations include logarithmically spacing level curves (either mapped on the surface or proje...
Article
Full-text available
The instant centers of velocity (ICs) of most planar mechanisms can be determined as the intersection of the lines of centers, also known as Aronhold-Kennedy lines, along which the ICs of three distinct links in relative motion are located. It is shown how these intersections can be kept track of in matrix form, very suitable to algorithmic impleme...
Conference Paper
Full-text available
Working Model 2D (WM 2D) is a powerful, easy to use planar multibody software that has been adopted by many instructors teaching Statics, Dynamics, Mechanisms, Machine Design, as well as by practicing engineers. Its programming and import-export capabilities facilitate simulating the motion of complex shape bodies subject to constraints. In this pa...
Article
The steering system of a compact wheeled tractor is analyzed using a commercial multi-body simulation software. The effect of axle-oscillation induced steering errors and of the axle impacting the bump stops attached to the tractor body is compared for two design variants. It is shown that by diminishing the kinematic cross-coupling between the ste...
Article
In this paper the problem of synthesizing the Ackermann linkage and the steering control mechanism of an adjustable tread-width tractor is presented. Several conflicting requirements were simultaneously considered as follows: ensuring minimum wheel-slip and symmetric steering control for left and right turns, ensuring minimum cross-coupling between...
Article
An experimental study of the effect of hydraulic vibrations on initiation of buckling and axial force transfer for helically buckled pipes at simulated horizontal wellbore conditions has been conducted. Hydraulic vibrations have been induced inside the drillpipe by interrupting the fluid flow at controllable frequencies. The results show that the h...
Article
A novel method for kinematic analysis of parallel-axes epicyclic gear trains is presented, called the incidence and transfer method, which uses the incidence matrices associated with the edge-oriented graph associated to the mechanism and the transfer joints (teeth contact joints). Relative to such joints, a set of independent equations can be gene...
Conference Paper
Full-text available
A new approach to solving constrained nonlinear programming problems using evolutionary computations is discussed. According to the method two populations are evolved, one population (females) is evolved inside the feasible domain of the design space and a second population (males) is evolved outside this feasible domain. Both populations can be in...
Article
Full-text available
The gear-teeth number synthesis of an automatic planetary transmission used in automobiles is formulated as a constrained optimization problem that is solved with the aid of an Estimation of Distribution Algorithm. The design parameters are the teeth number of each gear the number of multiple planets and gear module, while the objective function is...
Conference Paper
A novel method for kinematic analysis of parallel-axes epicyclic gear trains (EGT) is presented, called the incidence and transfer method (IT), which uses the incidence matrices associated to the edge-oriented graph attached to the mechanism and the transfer joints (teeth contact joints). Relative to such joints, a set of independent equations can...
Article
Full-text available
Cover crops may be rolled and crimped using an apparatus which may be rolled across a field at a relatively high speed without excessive vibration. The apparatus includes a substantially cylindrical drum which has a plurality of rows of outwardly extending blades projecting therefrom. The blades may be wave-shaped, curved, substantially straight an...
Article
Full-text available
Hypersurfaces of the type z=F(x1,...,xn), where F are single-valued functions of n real variables, cannot be visualized directly due to our inability to perceive dimensions higher than three. However, by projecting them down to two or three dimensions many of their properties can be revealed. In this paper a method to generate such projections is p...
Article
Full-text available
Rollers may provide a valuable alternative to chemicals for terminating a cover crop. Several producers are now using versions that they have made or have purchased. Most of these producers, however, complain about excessive vibration that is caused by the roller passing over the cover crop. To avoid this excessive vibration, they must limit their...
Conference Paper
Full-text available
Two variants of estimation of distribution algorithm (EDA) are tested solving several continuous optimization problems with constraints. Numerical experiments are conducted and comparison is made between constraint handling using several types of penalty and repair operators in case of both elitist and nonelitist implementation of the EDA's. Graphi...
Conference Paper
Full-text available
The gear-teeth number synthesis of an automatic planetary transmission used in automobiles is formulated as a constrained optimization problem that is solved with the aid of an Estimation of Distribution Algorithm. The design parameters are the teeth number of each gear, the number of multiple planets and gear module, while the objective function i...
Article
Full-text available
Thesis (Ph. D.)--Auburn University, 2004. Abstract. Includes bibliographical references.
Conference Paper
Full-text available
Computer programing is a fundamental discipline taught early in the curriculum to all undergraduate engineering majors. Fewer opportunities exist however for students to practice their programing skills before they graduate. In this paper, a number of computer programing exercises on planar mechanism kinematic simulation given to Mechanical Enginee...
Article
Full-text available
Based on the depth-sorting hidden-line removal algorithm, new methods of producing silhouette and raised level-curve diagrams with the hidden-lines removed of single-valued functions of two variables are presented. An algorithm of generating accurate truncated representations over the z-axis of the same types of functions is also described. These m...
Article
Full-text available
Parametric design charts are proposed for the central-lever steering linkage, generated for simplified reference configuration mechanisms, the geometry Of Which is defined by only four parameters. This highlights the fact, yet not generally acknowledged, that the steering law ensured by a mechanism with adjacent central joints (known as bell crank...
Article
Full-text available
The problem of optimum synthesis of the planar four-bar function generator is investigated and the practical case of the Ackermann steering linkage considered as an example. The reduced number of design parameters of this symmetric four-bar linkage allowed inspecting the design space of various types of objective functions through 3D representation...
Article
Full-text available
The paper deals with the optimum kinematic synthesis and analysis of the five-link independent suspension system (also known as “multilink” suspension, mechanism commonly symbolized 5S–5S). The synthesis goal is fulfilling a minimum variation of the wheel track, toe angle and camber angle during jounce and rebound of the wheel. Two solutions obtain...
Conference Paper
Full-text available
A method of inspecting the design space of multivariable objective functions is proposed. By scanning 1 or 2 of the variables at a constant step while partially minimizing or maximizing the function with respect to the remaining variables, sets of points are generated that can be fiarther used in producing 2D or 3D diagrams. A number of examples ar...
Conference Paper
Full-text available
Some of the design issues of the 7feet radius materials processing research centrifuge of the Solidification Design Center of Auburn University are presented. The centrifuge consists of a modified rear axle of a 6 ton truck disposed vertically on a steel structure, the wheel-hub of which rotates a horizontal arm. The two-stage gearbox and the angle...
Conference Paper
Full-text available
The guiding principles adopted for teaching the Comprehensive Mechanical Design course in the Department of Mechanical Engineering of Auburn University are presented. These were introduced to better serve the need for well-trained engineering personnel, where technical skills must be combined with good communication and management skills.
Conference Paper
Full-text available
An optimum orientation of the mold inside the spinning drum of a casting centrifuge is sought, at which the resulting g-force has a maximum overall value inside the part's volume. An optimization problem is defined and solved with the aid of a hybrid algorithm that combines an evolutionary algorithm named 3p in series with Nelder and Mead's simplex...
Conference Paper
Full-text available
The main features of a software named D_3D specially devised for visualizing objective functions as contour plots and 3D surfaces are presented. These include detailing the minimum areas by logarithmically spacing the level curves, the possibility of truncating the upper parts of the surface (particularly useful in representing penalized objective...
Article
Full-text available
A new proof of the existence of three function cognates of Stephenson II and two function cognates of Stephenson III mechanisms is presented, and a new class of overconstrained mechanisms of the 3RT3R Watt II type is described. In addition, some properties of four- and six-bar planar mechanisms are discussed, mainly in respect to the generation of...
Article
Full-text available
The paper presents a kinematic analysis of a two-degree-of-freedom (2-DOF) steering mechanism based on the Ackermann principle and of a type found in rigid-axle vehicles. Using an iterative approach to solve the equations of constraint, major features of the mechanism are investigated, e.g. sensitivity to geometry changes, steering errors induced b...
Article
Full-text available
Examples of graphical representations of single-valued functions of two variables which occur in the analysis and synthesis of linkage mechanisms are presented. The authors have developed their own software which has advantages over existing packages when examining penalised objective functions with very large peaks. The generated 3D surface and co...