Beam Element Structural Dynamics Modification Using Experimental Modal Rotational Data

Structural dynamic modification (SDM) of a fixed-free (cantilever) beam to convert it into a fixed-fixed beam with experimental modal data is presented. The SDM focuses on incorporating experimental rotational degrees-of-freedom (DOF) measured with a novel laser measurement technique. A cantilever beam is tested to develop the experimental modal database including rotational degrees of freedom. A modal database from a finite-element model also is developed for comparison. A structural dynamic modification, with both databases, is performed using a Bernoulli-Euler beam to ground the free end of the cantilever beam. The hardware is then modified and a second experimental modal analysis of the resulting fixed-fixed beam performed. A finite-element model of the fixed-fixed beam also was created. Comparison of results from these four tests are used to assess the effectiveness of SDM using experimental modal rotational data. The evaluation shows that provided high quality experimental rotational modal data can be acquired, SDM work with beam elements can be effective in yielding accurate results

Development and application of multiple-input models for structural noise source identification of forge hammers. Part II—Application

The application of multiple-input models to analyze structurally generated noise from a forge hammer is discussed. Part I of this article presented the rationale for developing and interpreting multiple-input models for structural noise source identification. An investigation of the transducer requirements for characterizing the sound radiation from a monolithic element showed that a single, well-placed accelerometer may be sufficient for each element. Part II of this article analyzes the application of the multiple-input modeling technique to the structural noise source identification of a Chambersburg #8 die forger. A comparison of three-, five-, and seven-input models applied to the forge hammer under production conditions indicates that as few as five transducers would suffice to characterize the sound contributions of the five structural elements. Analysis of these models indicates that the ram is the dominant source of sound energy, the columns are secondary sources, and the yoke and anvil are minor sources when detected through a microphone at the operator\u27s position. The analysis also shows that the coupling between the hammer structural elements is sufficient to render conventional wrapping identification methods unreliable for analyzing hammer noise. © 1984, Acoustical Society of America. All rights reserved

Development and application of multiple input models for structural noise source identification of forge hammers. Part I: Development

The application of multiple input models to analyze structurally generated noise from a forge hammer is discussed. Part I of this article is intended to present the rationale for application and analysis of multiple input models for noise source identification. The development of the empirical models is reviewed and investigated to show how the terms in the model can be interpreted to mathematically simulate the selective wrapping approach to source identification. The interaction of the structural excitation forces and radiated structural noise is examined for a four-piece forge hammer and provides an indication of the characteristic measurements needed to develop the multiple input model that is representative of the hammer\u27s sound radiation. The transducer requirements for application to forge hammers are examined through experiments performed on a laboratory test structure and a forge hammer column. The results indicate that a single, well-placed transducer may be sufficient to characterize the sound radiation from a monolithic element. Part II of this article analyzes the application of the techniques to a Chambersburg #8 die forger under production conditions. The experimental results indicate that the ram is the dominant source of sound energy, the columns are secondary sources, and the yoke and anvil are minor sources when detected through a microphone at the operator\u27s position. © 1984, Acoustical Society of America. All rights reserved

GLOBAL DISTRIBUTED ENGINEERING STUDENT DESIGN TEAMS: EFFECTIVENESS AND LESSONS LEARNED

Twenty-first century engineering student professional skills require the ability to work effectively in multicultural, globally distributed teams. Chalmers University of Technology (Sweden) and Penn State University (USA) have formed a collaboration to provide studentswith an experience in this environment to start requisite skill development. The activity is anchored by a corporate supplied project with realistic open-ended design requirements. The students are expected to mimic the operation of a multinational corporate engineering team todevelop a design solution. The collaboration was initiated in September 2014 and launched in January 2015 with Volvo Group as the industrial partner. In addition to the traditional design experience outcomes, the learning objectives from a global perspective are to: (a) understandthe impact of engineering in a global, economic, environmental, and societal context; (b) understand cultural/ethnic differences and develop the ability to work sensitively with them; (c) learn to function effectively in multinational teams; (d) communicate effectively in English,regardless of team members first language; and (e) develop the ability to organize and deliver communication around the globe. The paper discusses the integration of academic protocols from each university, the logistics and operation of the global student teams. At completion of the program a critique was performed from various perspectives to assess effectiveness and capture lessons learned. A pre and post survey was given to the students to assess effectson intercultural communication from the interaction. The Volvo Group personnel who interacted with the teams and supervising instructors were asked to critically evaluate the program. All information pointed to a successful program whereby the students delivered technically sound design solutions and gained professionally through the global experience. The paper concludes with a discussion of the keys to success for such a globally distributeduniversity-corporate academic collaboration