An Inverse Force Analysis of a Planar Two-Spring System

1995 ◽  
Vol 117 (4) ◽  
pp. 548-553 ◽  
Author(s):  
T. M. Pigoski ◽  
J. Duffy

A closed-form inverse force analysis was performed on a planar two-spring system. The two springs were grounded to pivots at one end and attached to a common pivot at the other. A known force was applied to the common pivot of the system, and it was required to determine all of the assembly configurations. By variable elimination, a sixth degree polynomial in the resultant length of one spring was derived, and from this, six real solutions of the point of application of force were obtained. Following this, the applied force was incremented along a line and the six paths of the moving pivot were tracked starting from the zero-load configurations. An analysis of these results showed stability phenomena indicating the workspace of this system contained regions of negative spring stiffness and points of catastrophe.

Author(s):  
Thomas M. Pigoski ◽  
Joseph Duffy

Abstract A closed-form inverse force analysis was performed on a planar two-spring system. The two springs were grounded to pivots at one end and attached to a common pivot at the other. A known force was applied to the common pivot of the system, and it was required to determine all of the assembly configurations. By variable elimination, a sixth degree polynomial in the resultant length of one spring was derived, and from this, six real solutions of the point of application of force were obtained. Following this, the applied force was incremented along a line and the six paths of the moving pivot were tracked starting from the zero-load configurations. An analysis of these results showed stability phenomena indicating the workspace of this system contained regions of negative spring stiffness and points of catastrophe.


1995 ◽  
Vol 117 (2A) ◽  
pp. 286-291 ◽  
Author(s):  
P. Dietmaier

A tetrahedral three-spring system under a single load has been analyzed and a closed-form solution for the equilibrium positions is given. Each of the three springs is attached at one end to a fixed pivot in space while the other three ends are linked by a common pivot. The springs are assumed to behave in a linearly elastic way. The aim of the paper at hand was to find out what the maximum number of equilibrium positions of such a system might be, and how to compute all possible equilibrium configurations if a given force is applied to the common pivot. First a symmetric and unloaded system was studied. For such a system it was shown that there may exist a maximum of 22 equilibrium configurations which may all be real. Second the general, loaded system was analyzed, revealing again a maximum of 22 real equilibrium configurations. Finally, the stability of this three-spring system was investigated. A numerical example illustrates the theoretical findings.


Author(s):  
J. P. Yin ◽  
G. K. Matthew ◽  
J. Duffy

Abstract A closed-form inverse force analysis was performed for a planar four-bar mechanism with a rigid coupler and frame but with compliance in the form of linear springs in the input and output links. A known force was applied to the coupler link on a line fixed in the plane containing the frame. A sixteenth degree polynomial in the tan-half-angle of the angular displacement of the output link was derived using algebraic elimination. A numerical result is presented which verifies the solutions.


Author(s):  
An-Xin Liu ◽  
Bao-Qian Shi ◽  
Ming Zhang ◽  
Ting-Li Yang

Abstract The inverse force analysis of planar three-spring system is studied in this paper. First, the force balance equations and moment balance equations, together with the loop equations, are reduced into polynomial form. Then continuation method is used to find all static equilibrium positions of the system.


Author(s):  
Mauro Rocha Baptista

Neste artigo analisamos a relação do Ensino Religioso com a sua evolução ao longo do contexto recente do Brasil para compreender a posição do Supremo Tribunal Federal ao considerar a possibilidade do Ensino Religioso confessional. Inicialmente apresentaremos a perspectiva legislativa criada com a constituição de 1988 e seus desdobramentos nas indicações curriculares. Neste contexto é frisado a intenção de incluir o Ensino Religioso na Base Nacional Curricular Comum, o que acabou não acontecendo. A tendência manifesta nas duas primeiras versões da BNCC era de um Ensino Religioso não-confessional. Uma tendência que demarcava a função do Ensino Religioso em debater a religião, mas que não permitia o direcionamento por uma vertente religioso qualquer. Esta posição se mostrava uma evolução da primeira perspectiva histórica mais associada à catequese confessional. Assim como também ultrapassava a interpretação posterior de um ecumenismo interconfessional, que mantinha a superioridade do cristianismo ante as demais religiões. Sendo assim, neste artigo, adotaremos o argumento de que a decisão do STF, de seis votos contra cinco, acaba retrocedendo ante o que nos parecia um caminho muito mais frutífero.Palavras-chave: Ensino Religioso. Supremo Tribunal Federal. Confessional. Interconfessional. Não-confessional.Abstract: On this article, we analyze the relation between Religious education and its evolution along the currently Brazilian context in order to understand the position of the Supreme Court in considering the possibility of a confessional Religious education. Firstly, we are going to present the legislative perspective created with the 1988 Federal Constitution and its impacts in the curricular lines. On this context it was highlighted the intention to include the Religious Education on the Common Core National Curriculum (CCNC), which did not really happened. The tendency manifested in the first two versions of the CCNC was of a non-confessional Religious Education. A tendency that delineated the function of the Religious Education as debating religion, but not giving direction on any religious side. This position was an evolution of the first historical perspective more associated to the confessional catechesis. It also went beyond the former interpretation of an inter-confessional ecumenism, which kept the superiority of the Christianity over the other religions. As such, in this paper we adopt the argument that the decision of the Supreme Court, of six votes against five, is a reversal of what seemed to be a much more productive path on the Religious Education.Keywords: Religious Education. Brazilian Supreme Court. Confessional. Inter-confessional. Non- confessional.Enviado: 23-01-2018 - Aprovado e publicado: 12-2018


2019 ◽  
Vol 62 (6) ◽  
pp. 88-99
Author(s):  
Andrey A. Lukashev

The typology of rationality is one of major issues of modern philosophy. In an attempt to provide a typology to Oriental materials, a researcher faces additional problems. The diversity of the Orient as such poses a major challenge. When we say “Oriental,” we mean several cultures for which we cannot find a common denominator. The concept of “Orient” involves Arabic, Indian, Chinese, Turkish and other cultures, and the only thing they share is that they are “non-Western.” Moreover, even if we focus just on Islamic culture and look into rationality in this context, we have to deal with a conglomerate of various trends, which does not let us define, with full confidence, a common theoretical basis and treat them as a unity. Nevertheless, we have to go on trying to find common directions in thought development, so as to draw conclusions about types of rationality possible in Islamic culture. A basis for such a typology of rationality in the context of the Islamic world was recently suggested in A.V. Smirnov’s logic of sense theory. However, actual empiric material cannot always fit theoretical models, and the cases that do not fit the common scheme are interesting per se. On the one hand, examination of such cases gives an opportunity to specify certain provisions of the theory and, on the other hand, to define the limits of its applicability.


2018 ◽  
Vol 8 (4) ◽  
pp. 65-69
Author(s):  
Mao Nguyen Van ◽  
Dong Tran Nam

Background: Pigmented tumour of the skin is one of the common tumour in human including the benign pigmented tumours (more common) called Nevi tumours and the malignant one called melanoma which was less frequent but the most poor in prognosis. In addition, the others not belonging to these group had the same clinical appearance, so the application of histopathology and immunohistochemistry for the definitive diagnosis was indespensible. Objectives: 1. To describe the macroscopic features of the pigmented tumoral-like lesions; 2. To classify the histopathologic types of the pigmented cell tumours and the other pigmented tumours of the skin. Materials and Method: Cross-sectional research on 55 patients diagnosed as pigmented tumoral lesions by clinician, then all definitively diagnosed by histopathology combining the immunohistochemistry in difficult cases. Results: There was no difference in gender, the disease was discovered most common in adult, especially with the age over 51 years old (58.1%). the most region located was in the face accounting for 60%, following the trunk and limbs (14.6%, 12.8% respectively). All 3 malignant melanomas happened in foot. The most common color of the lesions was black (65.4%), the other ones were rose, grey and blue. Histopathology and immunohisthochemistry showed that the true pigmented cell tumours were 52.6% encompassing benign ones (Nevi tumour) (41.8%), melanoma (5.4%) and lentigo (5.4%). 47.4% was not the true pigmented cell tumour including pigmented basocellular carcinoma (36.4%) and the others less common as histiofibromas, acanthoma and papilloma. Conclusion: the pigmented tumoral-like lesions of the skin could be the true pigmented cell tumours and the others, so the application of the histopathology and the immunohistochemistry after the clinical discovery helps to determine and classify the disease definitely and for the best orientation of treatment as well. Key words: skin tumour, benign pigmented tumour (Nevi), malignant pigmented tumour (melanoma), pigmented basocellular carcinoma


Author(s):  
Rakshith . ◽  
Shivakumar . ◽  
Sreeharsha . ◽  
Divyasree .

The core principles in Ayurveda give prime importance to Agni, Prakriti, Ahara (food) and Vihara (lifestyle) in maintaining health. Present era people are scheduled to one or the other works due to which they are following unrightful food and habits which lead the manifestation of one of the common disorder which troubles person a lot - Amlapitta. By excess “Hurry, Worry and Curry” GIT disorders are the most common, not only affecting physical health but also psychological and social health. Amlapitta is one of that and it is a burning problem of the whole World. Amalpitta is composed of word Amla and Pitta. Amlapitta is a very common disease caused by Vidagdha Pitta with features like Amlodgara, Tiktodgara, Hrit, Kantha Daha etc. Pathya recommended in Amlapitta are Yava, Godhuma, Purana Shali, Mudga Yusha, Lajasaktu etc. Apathya recommended in Amlapitta are Navanna, Avidugdha, Masha, Kulattha, Dadhi and etc. So this present review article throws light on Pathya (conducive) and Apathya (non conducive) in Amlapitta.


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