Joaquim Agullo | Universitat Politecnica de Catalunya (original) (raw)
Papers by Joaquim Agullo
The Journal of the Acoustical Society of America, 1988
Alternatives to the impulse response h(t) to describe the acoustical behavior of conical ducts. [... more Alternatives to the impulse response h(t) to describe the acoustical behavior of conical ducts. [The Journal of the Acoustical Society of America 84, 1606 (1988)]. Joaquim Agulló, Ana Barjau, Jordi Martínez. Abstract. In unidimensional ...
Multibody System Dynamics, 2014
This article proposes a simple linear-by-part approach for perfectly elastic 3D multiple-point im... more This article proposes a simple linear-by-part approach for perfectly elastic 3D multiple-point impacts in multibody systems with perfect constraints and no friction, applicable both to nonredundant and redundant cases (where the normal velocities of the contact points are not independent). The approach is based on a vibrational dynamical model, and uses the so called "independent contact space." Two different time and space scales are used. At the macroscale, the impact interval is negligible, and the overall system configuration is assumed to be constant. Consequently, the inertia and Jacobian matrices appearing in the formulation are also constant. The dynamics at the contact points is simulated through stiff springs undergoing very small deformations and generating system vibrations at the microscale. The total impact interval is split into phases, each corresponding to a constant set of compressed springs responsible for an elastic potential energy. For each phase, a reduced inertia matrix associated with a set of contact points, and a reduced stiffness matrix obtained from the potential energy (associated with all contact points undergoing compression) are introduced. From these matrices, a modal analysis is performed yielding an all-analytical solution within each phase. The main difference between the redundant and nonredundant cases concerns the inertia and stiffness matrices for modal analysis. While in the former case, both are related to the total set of contact points (total contact space), in the latter one they are related to two subsets: a subset of independent points for the inertia matrix (independent contact space), and the total set for the stiffness matrix. A second difference concerns the calculation of the normal impulses generated at each contact point. For the nonredundant case, they can be directly obtained from the total incremental normal velocities of the contact points through the inertia and stiffness matrices. For the redundant one, they can be obtained by adding up their incremental values at each impact phase. This requires an 498 A. Barjau et al. updating of a new effective stiffness matrix depending on the contact points undergoing compression at each phase. Four planar application cases are presented involving a single body and a multibody system colliding with a smooth ground.
Journal of Surveying Engineering, 2009
The three-point resection problem, i.e., the problem of obtaining the position of an unknown poin... more The three-point resection problem, i.e., the problem of obtaining the position of an unknown point from relative angular measurements to three known stations is a basic operation in surveying engineering. Several approaches to solve this problem, graphically or analytically, have been developed in the last centuries. In this paper, a new analytical approach to solve this problem is presented. The method determines the coordinates of the unknown point by intersecting straight lines through the three stations. The required azimuths of these lines are obtained from the geometric relationship between two similar triangles. Numerical simulations that show the good performance and accuracy of this approach are also reported.
Journal of Sound and Vibration, 1986
ABSTRACT
The Journal of the Acoustical Society of America, 1990
Acta Acustica united with Acustica
Page 1. 278 © S. Hirzel Verlag' EAA ACUSTICA . acta acustica Vol. 85 (1999) 278 - 284 Ac... more Page 1. 278 © S. Hirzel Verlag' EAA ACUSTICA . acta acustica Vol. 85 (1999) 278 - 284 Acoustic Propagation in Flaring, Axisymmetric Horns: I. A New Family of Unidimensional Solutions Joaquim Agull6, Ana Barjau Dep. of ...
Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de... more Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Revistes Catalanes amb Accés Obert (RACO). Identificador, http://www.raco.cat/index. php/ButlletiSCFQMT/article/view/132506. Título, Introducció al acústica de la tenora ...
Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de... more Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Revistes Catalanes amb Accés Obert (RACO). Identificador, http://www.raco.cat/index. php/ButlletiSCFQMT/article/view/132800. Título, Introducció al acústica de la tenora ...
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Contributions to science, Jan 1, 2011
Información del libro Introducció a les vibracions de n graus de llibertat: amb 20 qüestions amb ... more Información del libro Introducció a les vibracions de n graus de llibertat: amb 20 qüestions amb solució, 24 problemes amb resultat i 17 exemples d'aplicació.
Información del libro Introducció a la mecànica analítica, percussiva i vibratòria: amb 198 figur... more Información del libro Introducció a la mecànica analítica, percussiva i vibratòria: amb 198 figures, 80 qüestions amb solucions, 47 problemes amb resultats i 48 exemples d'aplicació.
The Journal of the Acoustical Society of America, 1988
Alternatives to the impulse response h(t) to describe the acoustical behavior of conical ducts. [... more Alternatives to the impulse response h(t) to describe the acoustical behavior of conical ducts. [The Journal of the Acoustical Society of America 84, 1606 (1988)]. Joaquim Agulló, Ana Barjau, Jordi Martínez. Abstract. In unidimensional ...
Multibody System Dynamics, 2014
This article proposes a simple linear-by-part approach for perfectly elastic 3D multiple-point im... more This article proposes a simple linear-by-part approach for perfectly elastic 3D multiple-point impacts in multibody systems with perfect constraints and no friction, applicable both to nonredundant and redundant cases (where the normal velocities of the contact points are not independent). The approach is based on a vibrational dynamical model, and uses the so called "independent contact space." Two different time and space scales are used. At the macroscale, the impact interval is negligible, and the overall system configuration is assumed to be constant. Consequently, the inertia and Jacobian matrices appearing in the formulation are also constant. The dynamics at the contact points is simulated through stiff springs undergoing very small deformations and generating system vibrations at the microscale. The total impact interval is split into phases, each corresponding to a constant set of compressed springs responsible for an elastic potential energy. For each phase, a reduced inertia matrix associated with a set of contact points, and a reduced stiffness matrix obtained from the potential energy (associated with all contact points undergoing compression) are introduced. From these matrices, a modal analysis is performed yielding an all-analytical solution within each phase. The main difference between the redundant and nonredundant cases concerns the inertia and stiffness matrices for modal analysis. While in the former case, both are related to the total set of contact points (total contact space), in the latter one they are related to two subsets: a subset of independent points for the inertia matrix (independent contact space), and the total set for the stiffness matrix. A second difference concerns the calculation of the normal impulses generated at each contact point. For the nonredundant case, they can be directly obtained from the total incremental normal velocities of the contact points through the inertia and stiffness matrices. For the redundant one, they can be obtained by adding up their incremental values at each impact phase. This requires an 498 A. Barjau et al. updating of a new effective stiffness matrix depending on the contact points undergoing compression at each phase. Four planar application cases are presented involving a single body and a multibody system colliding with a smooth ground.
Journal of Surveying Engineering, 2009
The three-point resection problem, i.e., the problem of obtaining the position of an unknown poin... more The three-point resection problem, i.e., the problem of obtaining the position of an unknown point from relative angular measurements to three known stations is a basic operation in surveying engineering. Several approaches to solve this problem, graphically or analytically, have been developed in the last centuries. In this paper, a new analytical approach to solve this problem is presented. The method determines the coordinates of the unknown point by intersecting straight lines through the three stations. The required azimuths of these lines are obtained from the geometric relationship between two similar triangles. Numerical simulations that show the good performance and accuracy of this approach are also reported.
Journal of Sound and Vibration, 1986
ABSTRACT
The Journal of the Acoustical Society of America, 1990
Acta Acustica united with Acustica
Page 1. 278 © S. Hirzel Verlag' EAA ACUSTICA . acta acustica Vol. 85 (1999) 278 - 284 Ac... more Page 1. 278 © S. Hirzel Verlag' EAA ACUSTICA . acta acustica Vol. 85 (1999) 278 - 284 Acoustic Propagation in Flaring, Axisymmetric Horns: I. A New Family of Unidimensional Solutions Joaquim Agull6, Ana Barjau Dep. of ...
Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de... more Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Revistes Catalanes amb Accés Obert (RACO). Identificador, http://www.raco.cat/index. php/ButlletiSCFQMT/article/view/132506. Título, Introducció al acústica de la tenora ...
Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de... more Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, Revistes Catalanes amb Accés Obert (RACO). Identificador, http://www.raco.cat/index. php/ButlletiSCFQMT/article/view/132800. Título, Introducció al acústica de la tenora ...
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Contributions to science, Jan 1, 2011
Información del libro Introducció a les vibracions de n graus de llibertat: amb 20 qüestions amb ... more Información del libro Introducció a les vibracions de n graus de llibertat: amb 20 qüestions amb solució, 24 problemes amb resultat i 17 exemples d'aplicació.
Información del libro Introducció a la mecànica analítica, percussiva i vibratòria: amb 198 figur... more Información del libro Introducció a la mecànica analítica, percussiva i vibratòria: amb 198 figures, 80 qüestions amb solucions, 47 problemes amb resultats i 48 exemples d'aplicació.