{"title":"Dynamic Analysis of Elastic Beam-Like Mechanism Systems","authors":"W. Ying, R. Huston","doi":"10.1115/1.3259046","DOIUrl":"https://doi.org/10.1115/1.3259046","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128817645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper considers the optimum structural design of vibrating beams in which the inertial axes and the elastic axes are noncollinear. The condition of noncollinear axes exists in structures having unsymmetric cross-sections. For unsymmetric cross-sections the centroid and the shear center do not coincide. This results in coupling between some of the bending and torsional modes. This paper presents results for the simply supported and cantilever beams with a thin-walled channel cross-section. The minimization of the structural volume subject to multiple frequency constraints and its dual problem of maximization of the fundamental frequency subject to a volume constraint are considered. A quadratic extended interior penalty function with Newton’s method of unconstrained minimization is used in structural optimization. The structures considered have nonstructural masses besides their own mass.
{"title":"Optimum Synthesis of Thin-Walled Vibrating Beams With Coupled Bending and Torsion","authors":"R. Grandhi, J. Moradmand","doi":"10.1115/1.3259037","DOIUrl":"https://doi.org/10.1115/1.3259037","url":null,"abstract":"This paper considers the optimum structural design of vibrating beams in which the inertial axes and the elastic axes are noncollinear. The condition of noncollinear axes exists in structures having unsymmetric cross-sections. For unsymmetric cross-sections the centroid and the shear center do not coincide. This results in coupling between some of the bending and torsional modes. This paper presents results for the simply supported and cantilever beams with a thin-walled channel cross-section. The minimization of the structural volume subject to multiple frequency constraints and its dual problem of maximization of the fundamental frequency subject to a volume constraint are considered. A quadratic extended interior penalty function with Newton’s method of unconstrained minimization is used in structural optimization. The structures considered have nonstructural masses besides their own mass.","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121683605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes several mechanical balancers, based on the planetary gear trains known as the hypotrochoid and epitrochoid trains, for reducing or eliminating second-order out-of-balance in mechanical systems. It is shown that by proper arrangement of the planetary gear trains, a balancer can be obtained for the elimination of second-order shaking forces or second-order shaking moments or a combination of both shaking forces and moments. The advantage of this type of balancer is that the carrier of the gear train needs only to run at the primary speed of the mechanical system to be balanced. Therefore, the balancer can be designed to be concentric with the primary rotating shaft of the machine using the primary shaft as the carrier. For example, for the balance of the second-order shaking force of an inline four-cylinder four-stroke internal combustion piston engine, the balancer can be placed on the third main bearing or one on each of the second and fourth main bearings.
{"title":"Planetary-Gear-Type Second-Harmonic Balancers","authors":"L. Tsai, E. R. Maki","doi":"10.1115/1.3259034","DOIUrl":"https://doi.org/10.1115/1.3259034","url":null,"abstract":"This paper describes several mechanical balancers, based on the planetary gear trains known as the hypotrochoid and epitrochoid trains, for reducing or eliminating second-order out-of-balance in mechanical systems. It is shown that by proper arrangement of the planetary gear trains, a balancer can be obtained for the elimination of second-order shaking forces or second-order shaking moments or a combination of both shaking forces and moments. The advantage of this type of balancer is that the carrier of the gear train needs only to run at the primary speed of the mechanical system to be balanced. Therefore, the balancer can be designed to be concentric with the primary rotating shaft of the machine using the primary shaft as the carrier. For example, for the balance of the second-order shaking force of an inline four-cylinder four-stroke internal combustion piston engine, the balancer can be placed on the third main bearing or one on each of the second and fourth main bearings.","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125651949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Probabilistic analysis of function generating mechanisms","authors":"R. H. Crawford, Singiresu S. Rao","doi":"10.1115/1.3259024","DOIUrl":"https://doi.org/10.1115/1.3259024","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116483687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Allocation of Dimensional Tolerances for Multiple Loop Planar Mechanisms","authors":"R. G. Fenton, W. Cleghorn, Jing-fan Fu","doi":"10.1115/1.3259022","DOIUrl":"https://doi.org/10.1115/1.3259022","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127488835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"‘Perfect’ Spring Equilibrators for Rotatable Bodies","authors":"D. Streit, B. Gilmore","doi":"10.1115/1.3259020","DOIUrl":"https://doi.org/10.1115/1.3259020","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"86 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114342594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the derivation of grashof-type movability conditions with transmission angle limitations for spatial mechanisms","authors":"J. Rastegar","doi":"10.1115/1.3259032","DOIUrl":"https://doi.org/10.1115/1.3259032","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115100136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enumeration of Basic Kinematic Chains Using the Theory of Finite Groups","authors":"E. Tuttle, S. W. Peterson, J. Titus","doi":"10.1115/1.3259028","DOIUrl":"https://doi.org/10.1115/1.3259028","url":null,"abstract":"","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114778439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract : A method of the spatial kinematic and dynamic analysis of deformable multibody systems subject to topology changes and impacts is presented. A pieced interval analysis scheme that accounts for the change in the spatial system topology due to the changes on the connectivity between bodies is developed. Deformable bodies in the system are discretized using the finite element method and accordingly a finite set of deformation modes is employed to characterize the system vibration. Even though there are infinitely many arrangements for deformable body axes, computational difficulties may be encountered due to the use of a limited number of deformation modes. Therefore, the deformable body references have to be carefully selected, and accordingly as the system topology changes, new bases for the configuration space to another, a set of spatial interface conditions or compatibility conditions that are formulated using a set of nonlinear algebraic equations are developed. The solution of these equations uniquely define the spatial configuration of the deformable multibody system after the change in the system kinematic structure. The techniques proposed in this research are applied to several technological system such as robotic manipulators and weapon systems. Keywords: Spatial kinematics; Dynamic analysis; Deformable multibody systems; Interval analysis scheme; Nonlinear algebraic equations.
{"title":"Spatial dynamics of deformable multibody systems with variable kinematic structure. Part 2. Velocity transformation","authors":"C. W. Chang, A. Shabana","doi":"10.1115/1.2912588","DOIUrl":"https://doi.org/10.1115/1.2912588","url":null,"abstract":"Abstract : A method of the spatial kinematic and dynamic analysis of deformable multibody systems subject to topology changes and impacts is presented. A pieced interval analysis scheme that accounts for the change in the spatial system topology due to the changes on the connectivity between bodies is developed. Deformable bodies in the system are discretized using the finite element method and accordingly a finite set of deformation modes is employed to characterize the system vibration. Even though there are infinitely many arrangements for deformable body axes, computational difficulties may be encountered due to the use of a limited number of deformation modes. Therefore, the deformable body references have to be carefully selected, and accordingly as the system topology changes, new bases for the configuration space to another, a set of spatial interface conditions or compatibility conditions that are formulated using a set of nonlinear algebraic equations are developed. The solution of these equations uniquely define the spatial configuration of the deformable multibody system after the change in the system kinematic structure. The techniques proposed in this research are applied to several technological system such as robotic manipulators and weapon systems. Keywords: Spatial kinematics; Dynamic analysis; Deformable multibody systems; Interval analysis scheme; Nonlinear algebraic equations.","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125978406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The foundations for an expert system shell for implementing mechanical design applications are presented in this paper. The shell supports facilities for knowledge acquisition, quasireactive planning, design evaluation, and subjective explanation. The underlying philosophy of each of these facilities and some preliminary implementation issues are discussed. A brief summary of a recent research effort and its implications on the development of a generalized expert system shell for implementing mechanical design applications are also presented
{"title":"A Generalized Expert System Shell for Implementing Mechanical Design Applications: Review, Introduction, and Fundamental Concepts","authors":"P. Premkumar, S. N. Kramer","doi":"10.1115/1.3259017","DOIUrl":"https://doi.org/10.1115/1.3259017","url":null,"abstract":"The foundations for an expert system shell for implementing mechanical design applications are presented in this paper. The shell supports facilities for knowledge acquisition, quasireactive planning, design evaluation, and subjective explanation. The underlying philosophy of each of these facilities and some preliminary implementation issues are discussed. A brief summary of a recent research effort and its implications on the development of a generalized expert system shell for implementing mechanical design applications are also presented","PeriodicalId":206146,"journal":{"name":"Journal of Mechanisms Transmissions and Automation in Design","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127169126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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