党的二十大胜利召开，吹响了以中国式现代化全面推进中华民族伟大复兴的前进号角。习近平总书记强调“教育、科技、人才是全面建设社会主义现代化国家的基础性、战略性支撑”，明确要求到 2035 年要建成教育强国、科技强国、人才强国。新时代新征程对科技界提出了更高的要求。当前，世界科学技术发展日新月异，不断开辟新的认知疆域，并成为带动经济社会发展的核心变量，新一轮科技革命和产业变革正处于蓄势跃迁、快速迭代的关键阶段。开展面向 2035 年的中国学科及前沿领域发展战略研究，紧扣国家战略需求，研判科技发展大势，擘画战略、锚定方向，找准学科发展路径与方向，找准科技创新的主攻方向和突破口，对于实现全面建成社会主义现代化“两步走”战略目标具有重要意义。

　　当前，应对全球性重大挑战和转变科学研究范式是当代科学的时代特征之一。为此，各国政府不断调整和完善科技创新战略与政策，强化战略科技力量部署，支持科技前沿态势研判，加强重点领域研发投入，并积极培育战略新兴产业，从而保证国际竞争实力。

　　擘画战略、锚定方向是抢抓科技革命先机的必然之策。当前，新一轮科技革命蓬勃兴起，科学发展呈现相互渗透和重新会聚的趋势，在科学逐渐分化与系统持续整合的反复过程中，新的学科增长点不断产生，并且衍生出一系列新兴交叉学科和前沿领域。随着知识生产的不断积累和新兴交叉学科的相继涌现，学科体系和布局也在动态调整，构建符合知识体系逻辑结构并促进知识与应用融通的协调可持续发展的学科体系尤为重要。

　　擘画战略、锚定方向是我国科技事业不断取得历史性成就的成功经验。科技创新一直是党和国家治国理政的核心内容。特别是党的十八大以来，以习近平同志为核心的党中央明确了我国建成世界科技强国的“三步走”路线图，实施了《国家创新驱动发展战略纲要》，持续加强原始创新，并将着力点放在解决关键核心技术背后的科学问题上。习近平总书记深刻指出：“基础研究是整个科学体系的源头。要瞄准世界科技前沿，抓住大趋势，下好‘先手棋’，打好基础、储备长远，甘于坐冷板凳，勇于做栽树人、挖井人，实现前瞻性基础研究、引领性原创成果重大突破，夯实世界科技强国建设的根基。”

　　作为国家在科学技术方面最高咨询机构的中国科学院和国家支持基础研究主渠道的国家自然科学基金委员会（简称自然科学基金委），在夯实学科基础、加强学科建设、引领科学研究发展方面担负着重要的责任。早在新中国成立初期，中国科学院学部即组织全国有关专家研究编制了《1956—1967 年科学技术发展远景规划》。该规划的实施，实现了“两弹一星”研制等一系列重大突破，为新中国逐步形成科学技术研究体系奠定了基础。自然科学基金委自成立以来，通过学科发展战略研究，服务于科学基金的资助与管理，不断夯实国家知识基础，增进基础研究面向国家需求的能力。2009 年，自然科学基金委和中国科学院联合启动了“2011—2020 年中国学科发展战略研究”。2012 年，双方形成联合开展学科发展战略研究的常态化机制，持续研判科技发展态势，为我国科技创新领域的方向选择提供科学思想、路径选择和跨越的蓝图。

　　联合开展“中国学科及前沿领域发展战略研究（2021—2035）”，是中国科学院和自然科学基金委落实新时代“两步走”战略的具体实践。我们面向 2035 年国家发展目标，结合科技发展新特征，进行了系统设计，从三个方面组织研究工作：一是总论研究，对面向2035 年的中国学科及前沿领域发展进行了概括和论述，内容包括学科的历史演进及其发展的驱动力、前沿领域的发展特征及其与社会的关联、学科与前沿领域的区别和联系、世界科学发展的整体态势，并汇总了各个学科及前沿领域的发展趋势、关键科学问题和重点方向；二是自然科学基础学科研究，主要针对科学基金资助体系中的重点学科开展战略研究，内容包括学科的科学意义与战略价值、发展规律与研究特点、发展现状与发展态势、发展思路与发展方向、资助机制与政策建议等；三是前沿领域研究，针对尚未形成学科规模、不具备明确学科属性的前沿交叉、新兴和关键核心技术领域开展战略研究，内容包括相关领域的战略价值、关键科学问题与核心技术问题、我国在相关领域的研究基础与条件、我国在相关领域的发展思路与政策建议等。

　　三年多来，400 多位院士、3000 多位专家，围绕总论、数学等18 个学科和量子物质与应用等 19 个前沿领域问题，坚持突出前瞻布局、补齐发展短板、坚定创新自信、统筹分工协作的原则，开展了深入全面的战略研究工作，取得了一批重要成果，也形成了共识性结论。一是国家战略需求和技术要素成为当前学科及前沿领域发展的主要驱动力之一。有组织的科学研究及源于技术的广泛带动效应，实质化地推动了学科前沿的演进，夯实了科技发展的基础，促进了人才的培养，并衍生出更多新的学科生长点。二是学科及前沿领域的发展促进深层次交叉融通。学科及前沿领域的发展越来越呈现出多学科相互渗透的发展态势。某一类学科领域采用的研究策略和技术体系所产生的基础理论与方法论成果，可以作为共同的知识基础适用于不同学科领域的多个研究方向。三是科研范式正在经历深刻变革。解决系统性复杂问题成为当前科学发展的主要目标，导致相应的研究内容、方法和范畴等的改变，形成科学研究的多层次、多尺度、动态化的基本特征。数据驱动的科研模式有力地推动了新时代科研范式的变革。四是科学与社会的互动更加密切。发展学科及前沿领域愈加重要，与此同时，“互联网 +”正在改变科学交流生态，并且重塑了科学的边界，开放获取、开放科学、公众科学等都使得越来越多的非专业人士有机会参与到科学活动中来。

　　“中国学科及前沿领域发展战略研究（2021—2035）”系列成果以“中国学科及前沿领域 2035 发展战略丛书”的形式出版，纳入“国家科学思想库 - 学术引领系列”陆续出版。希望本丛书的出版，能够为科技界、产业界的专家学者和技术人员提供研究指引，为科研管理部门提供决策参考，为科学基金深化改革、“十四五”发展规划实施、国家科学政策制定提供有力支撑。

　　在本丛书即将付梓之际，我们衷心感谢为学科及前沿领域发展战略研究付出心血的院士专家，感谢在咨询、审读和管理支撑服务方面付出辛劳的同志，感谢参与项目组织和管理工作的中国科学院学部的丁仲礼、秦大河、王恩哥、朱道本、陈宜瑜、傅伯杰、李树深、李婷、苏荣辉、石兵、李鹏飞、钱莹洁、薛淮、冯霞，自然科学基金委的王长锐、韩智勇、邹立尧、冯雪莲、黎明、张兆田、杨列勋、高阵雨。学科及前沿领域发展战略研究是一项长期、系统的工作，对学科及前沿领域发展趋势的研判，对关键科学问题的凝练，对发展思路及方向的把握，对战略布局的谋划等，都需要一个不断深化、积累、完善的过程。我们由衷地希望更多院士专家参与到未来的学科及前沿领域发展战略研究中来，汇聚专家智慧，不断提升凝练科学问题的能力，为推动科研范式变革，促进基础研究高质量发展，把科技的命脉牢牢掌握在自己手中，服务支撑我国高水平科技自立自强和建设世界科技强国夯实根基做出更大贡献。

“中国学科及前沿领域发展战略研究（2021—2035）”

联合领导小组            

2023 年 3 月            

　　力学是人类历史上对自然认识的第一次科学的理论概括，带动了自然科学的全面发展，并不断推进认识论与方法论的进步。力学将认识自然与工程技术发展结合，开启了人类大规模利用和改造自然的时代。马克思曾经说过：“力学是大工业的真正科学的基础。”钱学森曾说过：“不可能设想，不要现代力学就能实现现代化。”

　　力学催生了第一次工业革命，并对第二、第三次工业革命及正在发生的技术变革产生了重要推动作用，已成为支撑现代工业技术的基础学科，在世界各强国的科学技术布局中均占有独特地位。随着我国科学技术和经济社会的快速发展，力学无论是在创新研究能力上，还是在研究的广度和深度上都发生了深刻的变化，呈现出以下几个新特征：一是从研究对象看，当代力学既紧密围绕物质科学和复杂流动中的非线性、跨尺度、极端物性和极端使役环境等前沿问题，又直接面向高端装备、基础设施、能源环境、生命健康等重大需求，力学的前沿基础研究和应用研究同时发力，谋求良性互动；二是从研究手段看，现代工程系统、装备系统、生命系统日趋复杂，这要求力学建模更加精准，计算方法和实验技术不断更新，因此当代力学重视建立新模型和新理论，发展新算法和新实验技术，并在研制新软件、新仪器上抢占制高点；三是从发展趋势看，当代力学不仅通过广泛的多学科交叉产生了生物力学、环境力学、爆炸与冲击动力学、物理力学等新兴学科分支，而且深度融入材料、制造、能源、环境、健康等领域，不仅丰富了力学研究的内涵，同时扩充了力学服务国家创新驱动发展战略的广度与深度，使力学学科持续保持旺盛的生命力。

　　2019 年 8 月，在中国科学院和国家自然科学基金委员会的统一部署下，中国力学学科发展战略研究（2021～2035）工作正式启动，并成立了研究组和秘书组。胡海岩院士任研究组组长，郑晓静院士和何国威院士任研究组副组长；王铁军教授任秘书组组长，陆夕云院士、杨绍普教授、冯西桥教授和龙勉教授任秘书组副组长。

　　自中国力学学科发展战略研究（2021～2035）工作启动以来，研究组和秘书组多次召开工作会议，讨论和确定研究报告的指导思想、整体架构、体例等，研究新时代力学学科的定义、体系结构、优先发展领域、交叉研究领域、保障措施等重要问题。在 21 世纪以来历次力学学科发展战略研究成果的基础上，本次力学学科发展战略研究更加重视“四个面向”——面向世界科技前沿、面向经济主战场、面向国家重大需求、面向人民生命健康，着力体现力学学科在新时代的发展思路：一是重视力学学科的发展前沿，探索力学基础研究的新理论、新方法等；二是突出力学服务国家创新驱动发展战略，谋划与国家重大需求、国民经济发展和人民生命健康等密切相关的研究方向和能力建设；三是结合国家“十四五”规划、新型基础设施建设、国家重大计划、国家重大工程等，谋划新时代力学相关研究方向和应用领域。

　　本研究报告包括力学学科总论和力学学科各分支学科分论。在总论部分，重点论述力学学科的科学意义、战略价值、发展规律、研究特点、发展现状、发展态势、总体思路、发展方向、资助机制与政策建议等。在分论部分，分别论述力学各分支学科的相关问题，涉及动力学与控制、固体力学、流体力学和交叉力学（以生物力学、环境力学、爆炸与冲击动力学、物理力学为主）。邀请了各分支学科专家撰写相关条款，并通过多种方式，广泛征集了上述各分支学科的专家意见，并广泛征求了力学界相关学者的意见，使报告得到进一步的完善。

　　本研究报告是在研究组和秘书组充分调研和深入交流的基础上，由众多力学工作者共同完成的，得到众多力学专家的关心和帮助。国家自然科学基金委员会数学物理科学部孟庆国副主任、雷天刚处长和张攀峰处长高度重视力学学科发展战略研究工作，全程参与调研工作和历次工作会议，提出许多具体的意见和建议，对提升研究报告质量发挥了重要作用。在此一并致以衷心的感谢！

胡海岩             

《中国力学 2035 发展战略》研究组组长

2022 年 6 月         

　　力学是关于物质相互作用和运动的科学，研究介质运动、变形、流动的宏观与微观力学过程，揭示力学过程及其与物理学、化学、生物学等过程的相互作用规律与机理。力学为人类认识自然和生命现象、解决实际工程和技术问题提供理论基础与分析方法，是自然科学知识体系的重要组成部分，对科学技术的众多学科分支的发展起到支撑、引领与推动作用。我国具有完整的力学学科体系，包含动力学与控制、固体力学、流体力学等主要分支学科，以及生物力学、环境力学、爆炸与冲击动力学、物理力学等重要交叉学科。本报告共分为五章，报告内容包括力学总体及各分支学科的科学意义与战略地位、发展规律与研究特点、发展现状与发展态势、发展思路与发展方向，以及资助机制与政策建议。

　　1. 力学的科学意义与战略地位

　　力学是人类历史上对自然认识的第一次科学的理论概括，带动了自然科学的全面发展，并不断推进人类认识论与方法论的进步。力学把认识自然与工程技术发展结合起来，从而开启了人类大规模利用和改造自然的时代。马克思曾经说过：“力学是大工业的真正科学的基础。”钱学森曾说过：“不可能设想，不要现代力学就能实现现代化。”力学催生了第一次工业革命，并对第二、第三次工业革命及正在发生的技术变革产生了重要推动作用，已成为支撑现代工业技术的基础学科。力学具有旺盛的生命力，并不断自我完善，具有促进学科交叉、探求认知突破、应对复杂与不确定性系统、培养创新型和综合型人才的重要作用，在支撑社会现代化、增强原始创新能力、保障国家安全等方面具有不可替代性，在世界各强国的科学技术布局中均占有独特地位。

　　力学的科学意义与战略价值体现在如下五个方面。

　　（1）力学是重要的基础学科，与自然科学的众多学科深度交叉与融合，并对各门自然科学的发展起到重要的引导、示范与推动作用。

　　（2）力学是工程科学的基础，解决工程设计、制造和使役中的关键科学问题，对现代工业发展起着不可或缺的支撑作用。

　　（3）力学研究自然界与工程技术中最基本的作用规律与机制，具有鲜明的普适性和系统性特征，可以培养杰出的工程科学人才。

　　（4）力学具有持续而旺盛的生命力，始终与自然科学、工业技术及人类生命健康相伴而行，在我国创新驱动发展和现代化强国战略中具有关键作用。

　　（5）力学服务于现代工程和经济建设的诸多领域，同时具有广袤的疆域和强大的开拓能力，多学科交叉特点显著。

　　　2. 力学的发展规律与研究特点

　　（1）力学具有基础性和应用性，呈现“双力驱动”的发展规律。它不仅为现代科学奠定了重要基础，而且催生了第一次工业革命。当代力学发展既紧密围绕物质科学中的非线性、跨尺度等前沿问题，又直接面向高端装备、基础设施、能源环境、生命健康等重大需求。国际力学强国均在力学的基础研究和应用研究上同时发力，谋求两者良性互动。

　　（2）力学通过提出模型进行定量研究，且不断提升模型的描述和预测能力。现代工程系统日趋复杂，物理性质和使役环境日趋极端化，其力学研究要求建模更加精准，计算方法和实验技术不断更新。与此同时，当前的力学研究还针对力学计算、设计和控制，简化、验证和改进模型。国际力学强国均重视提出新模型、新理论、新计算方法、新测试技术，并在研制新软件、新仪器上抢占制高点。

　　（3）力学与众多学科产生交叉，在交叉中实现创新和发展。力学现象的普遍性和力学方法的普适性使力学与其他学科不断融合创新。当代力学不仅通过交叉产生了生物力学、环境力学、爆炸与冲击动力学、物理力学等新兴学科分支，而且深度融入制造、材料、能源、环境、健康等领域，解决重大技术问题。国际力学强国均重视学科交叉和融合创新。

　　3. 力学的发展目标、发展思路、主要研究方向和关键科学问题

　　我国已经形成了完整的力学学科体系，设有动力学与控制、固体力学、流体力学等分支学科，以及生物力学、环境力学、爆炸与冲击动力学、物理力学等交叉学科。我国力学学科发展呈现出由科学前沿和国家需求共同牵引的“双力驱动”规律，在基础研究和应用研究上同时发力，谋求两者互动。20 世纪 50 年代以来，力学在我国工业体系及国防体系建设中发挥了不可替代的重要作用。近年来，我国学者在力学国际顶级期刊上发表论文数和论文引用数量均位居世界第二；在国际理论与应用力学联盟（International Union of Theoretical and Applied Mechanics，IUTAM）中，我国是与美国并列的两个最高等级会员国之一；在高超声速飞行器、高速轨道交通、海洋装备等国家重大工程中，力学学科发挥了不可替代的重要作用。

　　1）发展目标

　　我国力学学科的发展目标是：服务国家创新驱动发展战略，到2035 年左右建设成为国际力学强国，为中华民族伟大复兴提供强有力的学科支撑。

　　2）发展思路

　　力学发展要坚持“四个面向”，即面向世界科技前沿、面向经济主战场、面向国家重大需求、面向人民生命健康，不断向科学技术的广度和深度进军。我国力学学科的发展思路如下。

　　（1）瞄准并开拓学科国际发展前沿，突出重点前沿基础研究，推进优势研究方向的发展，全面提升力学学科的研究水平，在主要研究方向上达到世界领先水平，在具有全局影响性的基础研究领域获得原创性重大研究成果，提高我国力学学科的国际地位和影响力。

　　（2）立足国家重大科技布局中的学科需求，突出重大需求牵引的应用基础研究。以实现科学原始创新为目标，发展力学学科的新概念、新理论、新方法和新测试技术，以支撑我国在航空航天、轨道交通、能源环境、海洋工程等领域的重大需求和国民经济的发展，为我国科学技术的自立自强做出引领性的贡献。

　　（3）积极促进与其他学科的交叉融合，拓展学科的研究领域和范围，积极培育新的学科生长点，促进新兴学科的发展与布局，服务国家重大需求和人民生命健康。

　　（4）加强力学人才培养，完善与提升力学教育体系，培养一批杰出的力学领军人才，打造一支高水平的力学研究队伍，建设一流力学学术期刊和交流平台，为我国经济社会发展和面对激烈国际科技竞争提供源头创新知识，高水平、高层次人才队伍，以及平台支撑。

　　（5）注重优势学科与薄弱学科的平衡。一方面，力学学科在与其他领域融合交叉的过程中产生了很多前沿和新兴领域，但这些前沿和新兴领域的学者数量相对较少，难以形成系统的学科；另一方面，在力学学科交叉融合的过程中，传统的力学基础学科开始呈现出“青黄不接”导致的净流失现象。由于这些前沿和新兴领域是力学学科的基础，若停滞不前终将影响整个学科的健康可持续发展，需要加以政策鼓励和扶持，加大经费支持力度，促成评价体系改革，从而吸引更多的学者，逐步扩大规模和影响。

　　（6）加强力学研究基地建设、大型实验平台建设与实验仪器设备研制。一方面，应布局建设能够支撑国家战略需求的力学类国家重点实验室。国家战略中涉及载人航天与探月、大型飞机、航空发动机与重型燃气轮机、核电装备、轨道交通、海洋工程平台等一系列重大装备和工程，各种大型结构与装备的设计与可靠性评价对力学提出了更高要求。另一方面，应布局建设面向国际前沿、多学科交叉的力学类国家重点实验室。面向力学学科的新增长点，应从长远布局建设面向多学科交叉同时以力学为主导的国家重点实验室。

　　3）主要研究方向和关键科学问题

　　我国力学学科的优先发展领域、主要研究方向和关键科学问题如下。

　　（1）复杂系统动力学机理认知、设计与调控。主要研究方向为非线性动力学、随机动力学、多体系统动力学；关键科学问题为含非线性、不确定性的动力学分析，复杂系统及其动态载荷辨识，系统动力学拓扑设计与控制。

　　（2）新材料的变形与破坏。主要研究方向为新材料的本构关系、破坏理论、多尺度力学行为、实验与计算新方法；关键科学问题为新材料的本构关系与强度理论、新材料的破坏失效行为、动态载荷下的新材料变形与破坏。

　　（3）新结构的力学设计与分析。主要研究方向为新结构设计、安全寿命评估、复杂载荷响应分析；关键科学问题为多功能驱动的新结构设计、重大装备的结构力学、新结构的复杂响应。

　　（4）高速流动的多物理过程。主要研究方向为流动过程中力、热、声等多因素耦合作用，流动计算模型，复杂流动现象的复现；关键科学问题为多物理过程耦合、复杂流动机制及控制、流动 - 运动 -变形耦合作用。

　　（5）湍流多尺度结构相互作用。主要研究方向为湍流多尺度结构的动力学、时空关联理论和模型、高精度计算和实验测量；关键科学问题为湍流多尺度结构演化、湍流时空耦合特征与湍流噪声、多相颗粒湍流、含相变的多相湍流。

　　（6）交叉力学。主要研究方向为极端条件下的复杂介质力学、多相多场功能系统的物理力学理论与方法、生命体的力学表征与调控；关键科学问题为极端条件下的复杂介质的演化，离散与连续关联的跨时空尺度力学，物理力学的理论与方法、实验方法与技术、信息和智能性质，生命介质的力学表征与跨尺度耦合，医疗与健康中的生物力学，生物材料设计与特殊环境生理适应性。

　　4. 资助机制与政策建议

　　研究资助体系对力学学科发展至关重要，主要思路是：保持基础研究队伍的适度规模，稳定支持力学基本科学问题和前沿领域的基础研究，引导结合国家需求开展基础研究，培养一批青年人才和优秀学术带头人。

　　针对我国力学学科的发展现状，特别提出保障力学学科发展的措施建议：强化力学的基础学科地位，促进力学学科的前沿发展；加大对力学实验方法和技术的支持力度，加快力学实验基地和实验平台的建设；加强力学计算支撑平台建设，推动国产力学计算软件发展；促进资源共享与合作交流平台建设，提高资源使用效率；重视学科交叉，促进创新型和复合型力学人才成长；加强人才队伍建设，积极培养优秀青年学者；大力提升力学类国内期刊的质量和影响力。

　　　5. 力学学科各分支学科

　　1）动力学与控制

　　动力学与控制是研究系统动态特性、动态行为与激励之间的关系及其调节的力学分支学科。动力学与控制学科的主要研究范畴包括自然界和工程领域中的动力学一般原理、系统建模，以及分析、设计与控制的理论和方法等。该学科以动态的观点研究高维、非线性、非光滑、不确定性、多场耦合、复杂网络等系统的运动形式、随时间变化规律及其控制策略，揭示力与系统运动之间的关系，有目标地调节系统的运动形式和动态特性，为认识自然现象和工程分析、设计提供理论方法和分析工具。

　　2）固体力学

　　固体力学是研究固体介质及其结构系统的受力、变形、破坏以及相关变化和效应的力学分支学科，是力学学科中规模最大的二级学科。固体变形与破坏几乎涉及人类生活的各个方面，如在各类结构与装备、各个工程技术领域，以及地震、滑坡、雪崩等多种自然灾害之中，均会出现固体的变形与破坏现象。固体物质具有多样性，其受力后的响应千差万别，具有明显的非线性和多尺度特征，如弹性、塑性、蠕变、断裂、疲劳等。固体力学研究各种载荷条件下材料与结构的变形与强度，为认识固体变形与破坏机理、工程结构与装备分析、设计和服役可靠性评价提供理论、方法和手段。

　　3）流体力学

　　流体力学是研究流体介质的特性、状态和在各种力的驱动下发生的流动以及质量、动量、能量输运规律的力学分支学科。流体介质广泛地存在于自然界和工程技术领域，从宇宙中巨大的天体星云到包围地球的大气层，从地球表面无垠的海洋到地球内部炙热的岩浆，从动物血管中的血液到各种工业管道内的石油和天然气。由于流体物理性质、流动状态和受力环境等复杂，流体力学问题呈现出非定常、非平衡、多尺度、多场耦合、强非线性等基本特征。流体力学的湍流问题是自然科学未解决的经典问题之一。流体力学为航空、航天、能源、交通领域的发展奠定了基础。

　　4）交叉力学

　　交叉性强是力学学科的一个基本特点。力学与其他科学之间的碰撞将推动力学在新时代的发展，成为力学进步的新动力。随着与其他学科的交叉越来越广泛与深入，力学所涉及对象的复杂性也越来越突出，出现了一系列处于科学前沿的新问题和新领域。交叉力学以力学为牵引，通过介质交叉、层次交叉、刚柔交叉、质智交叉等多个方面，实现多学科的交叉和融合。同时，力学作为科学与工程之间的桥梁，连接不同领域的基础与应用研究。交叉力学研究呈现出多场耦合、时空多尺度等复杂特征，其研究的深入与发展均离不开力学科学的发展，同时也催生出系列新概念、新理论和新方法。

Abstract

　　Mechanics refers to the science of interactions and movements of matters, focusing on the macro- and micro-mechanical processes of movement, deformation and flow of various media. It reveals the mechanical processes and mechanisms of interactions with physical, chemical, biological and other processes. Mechanics provides both theoretical basis and analytical methods for humans to understand natural and life phenomena and solve practical problems. As an important branch of natural sciences, it has led, supported and promoted the development of many branches of science and technology. A complete disciplinary system of mechanics has been established in China, which contains the major sub-disciplines such as dynamics and control, solid mechanics and fluid mechanics, as well as important inter-disciplines such as biomechanics, environmental mechanics, explosion and impact dynamics, and physical mechanics. This report consists of five chapters, which cover the scientific significance and strategic status, the development laws and research characteristics, the status and the trend of development, as well as the funding mechanism and policy recommendations for overall mechanics and each sub-discipline.

　　1. The scientific significance and strategic status of mechanics

　　Mechanics is the earliest summary of scientific theory in the history of natural cognition of human beings. It led to the overall development of natural sciences and continuously promoted the advancement of human epistemology and methodology. Mechanics combines human’s understanding of nature with the development of technology and engineering, opening up the era of large-scale utilization and transformation of nature. Karl Marx wrote that mechanics is the true scientific basis of large-scale industry. Xuesen Qian (Hsue-shen Tsien) once said that it is impossible to imagine that modernization would be achieved without modern mechanics. Mechanics gave birth to the first industrial revolution, played an important role in promoting the second and third industrial revolutions, and served as the fundamentals for technologies in modern industry. With vigorous vitality and continuous self-improvement, mechanics plays an important role in promoting inter-disciplinary fields, exploring cognitive breakthroughs, coping with complex and uncertain systems, and cultivating innovative and comprehensive talents. Mechanics is irreplaceable in supporting social modernization, enhancing original innovation capabilities and ensuring national security, occupying a unique position in the scientific and technological layout of world powers.

　　The past centuries have witnessed the strategic values of mechanics in the following five aspects.

　　(1) Mechanics is an important basic subject, deeply intersecting and integrating with many subjects of natural sciences, and plays an important role in leading, demonstrating and promoting the development of various natural sciences.

　　(2) Mechanics is the foundation of engineering science, which solves key scientific problems during the design, manufacturing and service of engineering systems, and plays an indispensable supporting role in the development of modern industry.

　　(3) Mechanics deals with the most basic rules and mechanisms of natural sciences, technology and engineering. With distinct universality and systematism, it cultivates outstanding talents in engineering science.

　　(4) Mechanics has a continuous and exuberant vitality, accompanied by the progress of natural sciences, technology and engineering, and human’s life and health, and plays a key role in the innovation-driven development and the modernization strategy in China.

　　(5) Mechanics serves various fields of modern engineering and economic construction, has a broad research area and powerful development ability, and has the remarkable characteristic of interdisciplinarity.

　　2. The development laws and research characteristics of mechanics

　　(1) Mechanics has both fundamentality and applicability, showing its law of development as what we call “driven by a pair of forces”. It not only laid an important foundation for modern science, but also gave birth to the first industrial revolution. Nowadays, the development of mechanics not only closely ties with the frontier issues of non-linearity and trans-scales in material science, but also involves the major needs such as the advanced equipment, infrastructures, energy and environment, as well as life and health. The world’s powers in mechanics all have been making their efforts to promote both basic research and applied research of mechanics, seeking a benign interaction between these two.

　　(2) Mechanics conducts quantitative research by establishing models, and continuously improves the description and prediction capabilities of the models. As the modern engineering systems become more and more complex, and the physical properties and service environment of those systems are more and more extreme, and the studies on their mechanics require more accurate mechanical modeling and repeatedly updating ofcomputational methods and experimental techniques. Meanwhile, the models need to be simplified, verified and modified for the purpose of computations, designs and controls. The world’s powers in mechanics all have been attaching importance to proposing novel models, theories, computational methods and experimental techniques, seizing the commanding heights in the development of new software and advanced instruments.

　　(3) Mechanics intersects with many subjects, achieving innovation and development during intersection. Mechanics continues to integrate and innovate with other disciplines due to the universality of phenomena and the applicability of methods of mechanics. Nowadays, new disciplines such as biomechanics, environmental mechanics, explosion and impact dynamics, as well as physical mechanics, have been developed from mechanics. Moreover, by deeply integrating into manufacturing, materials, energy, environments and human’s health, mechanics aims to solve major technical issues in these areas. The world’s powers in mechanics all have been attaching importance to inter-disciplinary and integrated innovation.

　　3. The development goals, development ideas, main research directions and key scientific issues of mechanics

　　A complete disciplinary system of mechanics has been established in China, with major sub-disciplines such as dynamics and control, solid mechanics and fluid mechanics, as well as inter-disciplines such as biomechanics, environmental mechanics, explosion and impact dynamics, and physical mechanics. The development of Chinese mechanics has been “driven by a pair of forces”. That is, a pair of driving forces comes from both frontiers of science and major needs of the nation. Great efforts have been made in basic research and applied research of mechanics to seek the interaction between these two. Mechanics has played an irreplaceable role in the construction of Chinese industrial system and national defense system since the 1950s. The numbers of both publications and citations of Chinese scientists in the top international journals of mechanics have ranked the second in recent years. China is one of the two highest-ranking state members alongside the United States of America in the International Union of Theoretical and Applied Mechanics (IUTAM). Mechanics has played an irreplaceable role in major state projects such as hypersonic flight vehicles, high-speed railway trains and marine equipment.

　　1) The development goals of mechanics

　　The development goals of Chinese mechanics are to serve the nation’s innovation-driven development strategy, to help China become a world powerhouse in mechanics by around 2035, and to provide strong disciplinary support for the great rejuvenation of the Chinese nation.

　　2) The development ideas of mechanics

　　The development of mechanics must adhere to the “Four Orientations”. That is, it should meet the specific needs of the frontiers of both science and technology in the world, the main economic battlefield, the major national needs, and human’s life and health, and continuously march into the breadth and depth of science and technology. The development ideas of Chinese mechanics are as follows.

　　(1) We should aim at the frontier of mechanics in the world, highlight the key basic researches in cutting-edge fields, promote the development of advantageous research directions, comprehensively improve the research level of mechanics, reach the world’s leading level in the main research directions, and make original and major achievements in basic researches with global influence, and improve the international status and influence of Chinese mechanics.

　　(2) Based on the disciplinary needs of the Chinese major scientific and technological layout, we should highlight the basic applied researches driven by major needs of the nation. With the goal of achieving original scientific innovations, we should propose novel concepts, theories, methods and experimental techniques in mechanics to meet the major needs of the nation in the fields of aerospace engineering, railway engineering, energy and environment engineering, and ocean engineering, and economic developments. We should make the leading contributions to the self-reliance and self-renewal of the nation in science and technology.

　　(3) We should actively promote the intersection and integration of mechanics and other disciplines, expand the research fields, and cultivate new disciplines, thereby promoting the development and layout of emerging disciplines and serving the major national needs and human’s life and health.

　　(4) We should strengthen the training of talents in mechanics, and improve and upgrade the educational system in mechanics. By cultivating a group of outstanding leaders in mechanics, building a highlevel research team in mechanics, and developing the top journals and communication platforms of mechanics, the mechanics discipline will provide original innovations, high-level and high-quality teams, and platforms to the Chinese economic and social developments and well cope with the fierce international technological competition.

　　(5) We should pay attention to the balance between superior and weak subjects. On the one hand, mechanics has developed many frontiers and emerging fields in the process of intersecting and integrating with other fields in recent years. However, the researchers in these frontiers and emerging fields are not enough, making it difficult for these fields to become systematic disciplines. On the other hand, there are not enough trained younger researchers ready to take over from older ones in traditional basic mechanics during the cross-integration process. As these frontiers and emerging fields are the foundations of mechanics, the stagnation will eventually affect the healthy and sustainable developments of the entire discipline. It is necessary, thus, to provide policy encouragement and funding support, and promote the reformation of the evaluation system, so as to attract more researchers and gradually expand the scale and influence of mechanics.

　　(6) It is essential to enhance the construction and development of research bases, large experimental facilities and advanced experimental instruments in mechanics. On the one hand, it is urgent to build the state key laboratories of mechanics that can support the national strategic needs, such as the space station and lunar exploration, large aircraft, aero-engines and heavy gas turbines, nuclear power equipment, offshore engineering platforms, large deep-sea platforms, and high-speed trains. Besides, the design and reliability evaluation of various large-scale structures and equipment have set higher requirements on mechanics. On the other hand, it is necessary to establish inter-disciplinary state key laboratories of mechanics oriented to the frontiers of science and technology. Facing the new developments of mechanics, the state key laboratories for mechanics-oriented multi-disciplines should be planned and constructed prospectively.

　　3) The main research directions and key scientific issues of mechanics

　　The development fields to which we should give priority, main research directions and key scientific issues of Chinese mechanics are as follows.

　　(1) Cognition, design and control of complex system dynamics. The main research directions are non-linear dynamics, stochastic dynamics and dynamics of flexible multibody system. The key scientific issues are the dynamic analysis with non-linearity and uncertainty, the identification of complex systems and their dynamic loads, and the topology design and control of systems dynamics.

　　(2) Deformation and failure of novel materials. The main research directions are constitutive laws of novel materials, the failure theories, the multi-scale mechanical behaviors, and the new computational and experimental techniques. The key scientific issues are the constitutive laws and strength theories of novel materials, the destruction and failure behaviors of novel materials, and the deformation and failure of novel materials under dynamic loads.

　　(3) Mechanical design and analysis of new structures. The main research directions are the design of new structures, the evaluation of safety and service life, and the response analysis of complex loads. The key scientific issues are the new structure design driven by multifunctions, the structural mechanics of major equipment and the complex response of new structures.

　　(4) The multi-physical processes of high-speed flow. The main research directions are the coupling effect of forces, heat, sound and other factors in complex flows, the computational model of flow, and the reproduction of complex phenomena. The key scientific issues are the coupling of multi-physical processes, the complex flow mechanism and control, and the flow-motion-deformation coupling effect.

　　(5) The multi-scale interaction in turbulent flows. The main research directions are the dynamics of multi-scale structures of turbulence, the theories and models of spatial-temporal correlation, and high-precision computations and experimental measurements. The key scientific issues are the evolution of multi-scale structures of turbulence, the spatial-temporal coupling characteristics of turbulence and turbulent noise, the multiphase particle turbulence, and the multiphase turbulence with phase transitions.

　　(6) X-mechanics. The main research directions are the complex medium mechanics under extreme conditions, physical mechanics theories and methods of multiphase and multi-field functional systems, and the mechanical characterization and control of living bodies. The key scientific issues are the evolution of complex media under extreme conditions, cross-temporal and spatial scale mechanics of discrete and continuous correlation, the theories and methods associated with information and intellectual properties of physical mechanics, the mechanical characterization and cross-scale coupling of living media, biomechanics in medical care and health, and the design of biomaterial and physiological adaptation to special environment.

　　4. The funding mechanism and policy recommendations

　　The funding system plays a vital role in the development of mechanics, which includes maintaining an appropriate scale of basic research teams, stably supporting the researches in basic mechanics issues and frontier fields, guiding the integration of the national needs to conduct basic researches, and cultivating a group of young talents and outstanding academic leaders.

　　In view of the development status of Chinese mechanics, we make special suggestions for the disciplinary development of mechanics as follows. It is better to strengthen the status of the basic discipline of mechanics and promote the frontier development of mechanics, to increase f inancial support to experimental methods and technologies of mechanics so as to speed up the construction of experimental bases and experimental facilities, to support the construction of the computing platform for mechanics so as to promote the development of domestic computational mechanics software, to promote the construction of resource sharing and cooperation platform so as to improve the efficiency of resource utilization, to attach importance to inter-disciplinary fields and promote the cultivation of innovative and compound talents of mechanics, to strengthen the construction of talent teams and actively train young scholars, and to vigorously improve the quality and influence of domestic journals of mechanics.

　　5. Brief introduction to the sub-disciplines of mechanics

　　1) Dynamics and control

　　Dynamics and control is a sub-discipline of mechanics. It deals with the dynamic characteristics of a system, the relations between dynamic behaviors and excitations of a system, and their adjustments as well. The main research areas of the sub-discipline include the general principles of dynamics in nature and engineering, system modeling, and theories and methods of analysis, design and control, etc. This sub-discipline studies the motion forms, and the variation laws and their control strategies with time in high-dimensional, non-linear, non-smooth, uncertain, multifield coupling and complex networks etc. from the dynamic perspective, revealing the relations between excitations and system responses. It can purposefully adjust the motion form and dynamic characteristics of a system, and provide theoretical methods and analysis tools for understanding natural phenomena and engineering analysis and design.

　　2) Solid mechanics

　　Solid mechanics is a sub-discipline of mechanics, dealing with the force, deformation, destruction, and related changes and effects of solid media and structural systems. As the largest sub-discipline of mechanics, solid mechanics occupies an important position in the evolution of human civilization. The deformation and destruction of solids are associated with almost all aspects of human activities, especially various structures and equipment in engineering fields, and serious natural disasters such as earthquakes, landslides and avalanches. Solid matters and their responses to forces are diversified, with obvious non-linear and multi-scale characteristics, such as elasticity, plasticity, creep, fracture and fatigue. Solid mechanics studies the deformation and strength of materials and structures under various loads, and provides theories, methods and means for understanding solid deformation and failure mechanisms, the engineering structure and equipment analysis, and the evaluation of design and service reliability.

　　3) Fluid mechanics

　　Fluid mechanics is a sub-discipline of mechanics, and studies the characteristics, flow states and and flow driven by various forces of fluid media, as well as the laws of mass, momentum and energy transportation. Fluid media widely exist in nature and engineering fields, from the vast nebulae of the universe to the atmosphere that surrounds the Earth, from the endless ocean on the surface of the Earth to the hot magma inside the Earth, and from the blood in animal blood vessels to the oil and gas in industrial pipelines. Due to the complexity of fluid physical properties, flow states and force environments, the problems of fluid mechanics show basic characteristics such as unsteadiness, nonequilibrium, multi-scale, multi-field coupling, and strong non-linearity. The fluid turbulence is one of the unsolved classic problems of natural sciences. Moreover, fluid mechanics has laid the foundation for the development of many engineering fields, such as aerospace, energy and transportation industries.

　　4) X-mechanics

　　X-mechanics refers to the modern inter-disciplinary branches of mechanics. Strong inter-disciplinary is a basic characteristic of mechanics. The collision between mechanics and other sciences promotes the development of mechanics in the new era and becomes a new driving force for the progress of mechanics. As the intersection becoming more and more extensive and in-depth, the complexity of the objects of concern has become more and more prominent. As such, a series of new problems and new fields at the frontiers of science has emerged. X-mechanics takes mechanics as the traction and achieves the intersection and integration of multiple disciplines through the multi-medium integration, the multilevel integration, the integration of rigid and flexible bodies, and the integration of objects and intelligence. Meanwhile, mechanics serves as a bridge between science and engineering, connecting basic and applied researches in different fields. The research on X-mechanics shows complex characteristics such as multi-field coupling and spatial-temporal multi-scales. The development of X-mechanics is inseparable from the development of mechanics and gives birth to a series of novel concepts, theories and methods.