Kinematics and Dynamics for Practicing Engineers Lecture 11: Dynamics of the Four‐Bar Pendulum – An Introduction to Constraints

Discipline: Flight Mechanics Abstract: Most of the technical literature on mechanical constraints is so encumbered with abstract mathematics that it has been rendered essentially useless from an engineering perspective. In this talk, a plain‐English explanation, replete with examples, is presented on the differences between holonomic and nonholonomic constraints and how to formulate equations of motion when either type of constraint is present in a mechanical system. About the Speaker: David Levinson has 47 years of experience as a dynamicist in the space industry, where he has been responsible for producing special purpose computer programs for simulating motions of complex mechanical systems, such as multibody spacecraft, robotic devices, and aerospace mechanisms. Mr. Levinson, currently retired, was employed at Lockheed Martin (formerly Lockheed Missiles and Space Company) from 1977 to 2013, and at Maxar Space Systems (formerly Space Systems Loral) from 2013 to 2024. Over the years, Mr. Levinson has been the recipient of numerous engineering awards, among them the American Institute of Aeronautics and Astronautics (AIAA) San Francisco Section Outstanding Young Engineer Award, the AIAA San Francisco Section Engineer of the Year Award in Astronautics, the AIAA San Francisco Section Engineering Educator of the Year Award, the American Society of Mechanical Engineers (ASME) Santa Clara Valley Section Distinguished Mechanical Engineer Award, the American Astronautical Society (AAS) Outstanding Achievement Award, and the Lockheed Missiles and Space Company President’s Award. Mr. Levinson is the author or coauthor of 43 published technical papers, and a coauthor of the two McGraw-Hill textbooks, Spacecraft Dynamics and Dynamics: Theory and Applications, as well as four desktop-published mechanics textbooks. He is also the author of the desktop-published undergraduate textbook Dynamics for Engineering Analysis. Mr. Levinson is a Fellow of both the AAS and the ASME, and is an Associate Fellow of the AIAA. As a participant in the Discover “E” K-12 engineering outreach program for more than 20 years, he has given 270 classroom presentations to middle school and high school students and teachers about careers in engineering. He is a popular speaker, and was an ASME Distinguished Lecturer from 2000 through 2004. For more than forty years he has lectured on technical subjects to a wide variety of audiences, including Cub Scouts, fifth graders, swimming coaches, middle school and high school students, school teachers, Kiwanis and Rotary clubs, physicians, practicing engineers, engineering graduate students, and university professors.

David Levinson

8/18/2025 8:00:00 PM