[转帖]锁志刚：What's wrong with Applied Mechanics?

绿荷雨丝

(Originally posted on Applied Mechanics News in 16 May 2006)

What's wrong with Applied Mechanics?

Applied Mechanics is a discipline that studies the response of matter to external forces, such as flow of a liquid, fracture of a solid, sound in the air, and vibration of a string. Applied Mechanics bridges the gap between fundamental physical sciences and wide-ranging applications. Representive questions are how a gecko climbs, how an earthquake occurs, how a computer chip fails, how an airplane flies, or how the Twin Towers fell. Major approaches include formulating concepts and theories, discovering and interpreting phenomena, as well as developing experimental and computational tools. For well over a century, Applied Mechanics has been a flagship discipline in the innovation of research, eduction, and community building in many branches of engineering, including Mechanical Engineering, Civil Engineering, Aerospace Engineering, Materials Engineering, and Bioengineering.

Despite the intellectual depth and practical utility, the discipline of Applied Mechanics is in a state of crisis, largely due to its own success. Like many sophisticated fields of science and engineering, Applied Mechanics constitutes a large chunk of knowledge, accumulated over millennia, represented by texts, equations, graphics, photos, audios, videos. This large quantity of knowledge has made it hard for any individual to master (and to add to) the field, a fact at least partially responsible for turning many talented young people away from the field. However, nobody has ever questioned the immense value of Applied Mechanics to a broad range of human activities today and to our posterity. Furthermore, new problems constantly emerge that requires ingenious use of existing knowledge, or fundamental progress in Applied Mechanics.

Still, the question remains, How do we impart this large chunk of knowledge to individuals within a reasonable amount of time, so that they still have time left to innovate?

A classical answer to this question dates back at least to Stephen P. Timoshenko, considered by many the father of modern Applied Mechanics. Starting early last century, Timoshenko and his followers divided the field of Applied Mechanics into subfields (such as strength of materials, theory of elasticity, theory of vibration, plates and shells, structural instabilities), and then summarized the "essential knowledge" in each subfield in a textbook. The success of this divide-and-conquer approach is immense, as attested by the rising importance of Applied Mechanics in engineering curriculum, by the fundamental progress (e.g., in fracture mechanics and in nonlinear continuum mechanics), and by pervasive use of Applied Mechanics in engineering practice.

This approach, however, is not scalable. As more results accumulate in a subfield, its textbook becomes thicker and more abstruse. As new subfields emerge, new textbooks are added to the pile. Furthermore, what is considered essential knowledge for a practicing engineer is very different from that for an undergraduate student. This and other idiosyncrasies of people lead to more textbooks, each with smaller audience. Individuals agonize over which cherries to pick, leaving most fruits untasted. Sadly, few mechanicians today consider writing textbooks professionally rewarding. Sadder still, the approach has led the discipline to fragment.

The fragmentation has been partially mitigated by the rise of computational mechanics. Over the last half century or so, the use of computer to solve complex, nonlinear boundary-value problems in the field of Applied Mechnaics has flourished, leading to commercial software like ABAQUS. Using such software, an electrical engineer, say, with a rudimentary understanding of mechanics, can analyze the strain field in the channel of a transistor. While computational mechanics has begun to unify Applied Mechanics, this unification is incomplete. For one, not all problems are suitable for numerical computation; many problems are solved by experiments combined with scaling laws, and by relating to previously solved problems. Some problems are solved more sensibly by trial and error. (Nobody learns to ride a bicycle by numerical simulation.) Also, to make a fundamental contribution to Applied Mechanics, one has to go beneath software and acquire a holistic understanding of the field.

I believe that the Internet will further unify Applied Mechanics by going beyond numerical computational aspects of mechanics, by making the labor of discovering and synthesizing knowledge more efficient and meaningful, and by making Applied Mechanics useful to more people.

绿荷雨丝

锁志刚教授简历

1985年毕业于西安交通大学工程力学系，1989年在哈佛大学获博士学位，1995年起任加州大学教授，1997 年起任普林斯顿大学教授，2002年起任哈佛大学Gordon McKay教授。2002年受聘我校“长江学者”讲座教授。现任ASME J Electronic Packaging副主编、J Applied Mechanics 等期刊编委、ASME电子材料委员会主席等多个学术职务，发起和组织了多个国际学术会议，作了百余次国际学术大会邀请报告和学术讲座。

在力学与材料科学的诸多领域进行了开创性研究，包括：界面断裂、电迁移、铁电致材料失效、纳米尺度的相分离与自组装、电子封装力学、薄膜力学等。发表论文百余篇，他引几千篇次。1992年获美国总统奖，2001年获得了ASME应用力学委员会“青年力学研究特别成就奖”等。

xinyuxf

没有听说过。不过Goolgle了一下，吓了一跳。真正的牛人！年轻有为阿

zhpurple

真的是很厉害的人物啊。:@o 这么看来西安交通大学工程力学系还很是不错的。

coldwind042

敬佩！！！

无水1324

牛人，涉及的面太广了吧？