第一届Rodney Hill奖获得者Michael Ortiz教授研究工作简评

Michael Ortiz ,加州理工学院航空与机械工程Dotty and Dick Hayman教授,美国文理学院院士,由于其在1998至2007年之间的出色研究成果荣获ICTAM2008年度Rodney Hill Prize。Rodney Hill固体力学奖和Batchelor流体力学奖是国际理论与应用力学协会设立的,旨在奖励研究者在过去十年内在其力学研究的分支中所取得重要贡献的两奖项。Ortiz教授是Rodney Hill 奖的第一位获奖人。      

非线性断裂力学

“非线性断裂力学”,系由美国应用力学系著名断裂专家J.W.Hutchinson教授所著,该书于1979年由丹麦理工大学固体力学系出版。 Hutchinson教授是非线性理论的开拓者之一,他对这一领域的精深研究使他成为第十五届国际理论和应用力学大会在该领域的特邀专题报告人。     

编者的话

为反映力学在工程实际中的应用和学科上的进展,及时交流运用近代力学理论、计算方法和实验技术在解决重大的工程实际问题中取得的新成果,在唐照千教授的倡导下,西安交通大学主办的《应用力学学报》于1984年9月正式创刊出版。唐照千教授为第一任主编,     

兰州大学力学专业发展的历史沿革

兰州大学力学专业是在原兰州大学数力系力学教研室基础上组建的，经过半个世纪的发展，已从原来单一的固体力学硕士点、博士点发展到今天的力学一级硕士点和固体力学与工程力学两个二级博士点及拥有力学一级博士后科研流动站等较为齐全的力学学科格局；以及拥有西部灾害与环境力学教育部重点实验室科研平台和理论与应用力学甘肃省科学研究与人才培养基地等。科学研究已从上世纪50~80年代的板壳非线性力学领域研究发展到今天的电磁固体力学、智能结构与动力控制、多场耦合与风沙环境力学等多学科交叉的特色研究领域与研究方向。     

复合材料结构力学

复合材料结构力学研究复合材料的杆、板、壳及其组合结构的应力分析、变形、稳定和振动等各种力学问题,在广义上属于复合材料力学的一个分支。由于其内容丰富,问题重要和研究对象不同,已成为和研究复合材料力学问题的狭义复合材料力学并列的学科分支。Ⅰ.复合材料结构的力学特点      

钱学森对近代力学的发展所做的贡献

钱学森先生为了研究实现高速飞机和远程火箭的可能性,在空气动力学、固体力学、稀薄气体力学和飞行力学等应用力学领域做出了杰出的贡献;并且开创了喷气推进学、工程控制论和物理力学等技术科学新分支.他对近代力学以至技术科学的内涵和发展方向,发表过全面系统的论述.在这篇文章中将介绍他的主要研究成果,并对他的科学思想作一初步的探讨.      

《固体力学学报》征稿简则

1.本刊是固体力学学科的学术性刊物。主要登载具有创造性的固体力学理论、实验和应用研究论文、各重要分支问题的评述和展望以及研究简报与学术讨论等,广泛交流学术界所取得的新研究成果,以促进固体力学学科的发展。读者对象是从事固体力学工作的科研与工程技术人员、高等院校教师和研究生。本刊有中、英文两个版本,向国内外公开发行。2.文稿必须是未在其它刊物上发表的论文。     

《固体力学学报》征稿简则

<正>1.本刊是固体力学学科的学术性刊物。主要登载具有创造性的固体力学理论、实验和应用研究论文、各重要分支问题的评述和展望以及研究简报与学术讨论等,广泛交流学术界所取得的新研究成果,以促进固体力学学科的发展。读者对象是从事固体力学工作的科研与工程技术人员、高等院校教师和研究生。本刊有中、英文两个版本,向国内外公开发行。     

《固体力学学报》征稿简则

正1.本刊是固体力学学科的学术性刊物。主要登载具有创造性的固体力学理论、实验和应用研究论文、各重要分支问题的评述和展望以及研究简报与学术讨论等,广泛交流学术界所取得的新研究成果,以促进固体力学学科的发展。读者对象是从事固体力学工作的科研与工程技术人员、高等院校教师和研究生。本刊有中、英文两个版本,向国内外公开发行。     

《固体力学学报》征稿简则

正1.本刊是固体力学学科的学术性刊物。主要登载具有创造性的固体力学理论、实验和应用研究论文、各重要分支问题的评述和展望以及研究简报与学术讨论等,广泛交流学术界所取得的新研究成果,以促进固体力学学科的发展。读者对象是从事固体力学工作的科研与工程技术人员、高等院校教师和研究生。本刊有中、英文两个版本,向国内外公开发行。     

On the L_p intersection body

In this paper,by using the Brunn-Minkowski-Firey mixed volume theory and dual mixed volume theory,associated with L_p intersection body and dual mixed volume,some dual Brunn-Minkowski inequalities and their isolate forms are established for L_p intersection body about the normalized L_p radial addition and L_p radial linear combination.Some properties of operator Lp are given.     

Preparation and characterization of LiAl_xCo_yNi_1-x-yO₂ particles

Lithium-aluminum-cobalt-nickel oxide LiAlxCoyNi1xyO2 particles, generally used as cathode of lithium battery, were prepared by chemical coprecipitation from an aqueous solution of LiOH, Al(NO3)3, Co(NO3)2 and Ni(NO3)2 with NH4OH. XRD, SEM and FTIR were used to examine the effect of nickel content on the product. FTIR patterns showed that increase in nickel content decreased the absorption strength of the peak of spinel structure of the product, attributed to the occupation by nickel in the aluminum sites. Particle size and electrical properties of the lithium-aluminum-cobalt-nickel oxide (abbreviated as LACNO) particles were also determined.     

Differential Independence of <Emphasis Type="Italic">Γ</Emphasis> and <Emphasis Type="Italic">ζ</Emphasis>

In a celebrated theorem H?lder proved that the Euler Γ-function is differential transcendental, i.e. Γ(z) is not a solution of any (non-trivial) algebraic ordinary differential equation with coefficients that are complex numbers; and we extend his methods to the Riemann ζ-function. Moreover, we conjecture that Γ and ζ are differential independent, i.e. Γ(z) is not a solution of any such algebraic differential equation—even allowing coefficients that are differential polynomials in ζ(z). However, we are able to demonstrate only the partial result that Γ(z) and ζ(sin 2πz) are differential independent.     

Reduction of<Emphasis Type="Italic">K</Emphasis><Subscript>I</Subscript> and<Emphasis Type="Italic">K</Emphasis><Subscript>II</Subscript> by the shape-memory effect in a TiNi shape-memory fiber-reinforced epoxy matrix composite

Shape-memory TiNi fiber-reinforced/epoxy matrix composites have been fabricated, and the suppression of crack-tip stress intensity and the change in fracture toughness have been systematically investigated. Stress-strain data for these composite specimens with notches at various angles and different crack lengths in the transverse direction have been measured in tensile tests. The stress intensity factor at the crack tip is experimentally determined from photoelastic fringe patterns. The decreases inK values are attributed to the compressive stress field in the matrix induced when the pre-strains of the TiNi fiber contract to their initial length upon heating above the austenitic final temperature. We present the influences of the pre-strain of TiNi fibers and the compressive domain size between a crack tip and fiber on theK value.     

Inequalities relating to Lp-version of Petty＇s conjectured projection inequality

Petty＇s conjectured projection inequality is a famous open problem in the theory of convex bodies. In this paper, it is shown that an inequality relating to Lp-version of the Petty＇s conjectured projection inequality is developed by using the notions of the Lp-mixed volume and the Lp-dual mixed volume, the relation of the Lp-projection body and the geometric body Г-pK, the Bourgain-Milman inequality and the Lp-Bnsemann-Petty inequality. In addition, for each origin-symmetric convex body, by applying the Jensen inequality and the monotonicity of the geometric body Г-pK, the reverses of Lp-version of the Petty＇s conjectured projection inequality and the Lp-Petty projection inequality are given, respectively.     

An experimental—Numerical evaluation of the<Emphasis Type="Italic">T</Emphasis><Stack><Subscript>ε</Subscript><Superscript>*</Superscript></Stack> integral for a three-dimensional crack front

TheT _ε ^* integral was calculated on the surface of single edge notched, three-point bend (SE(B)) specimens using experimentally obtained displacements. Comparison was made withT _ε ^* calculated with the measured surface displacements andT _ε ^* calculated at several points through the thickness of a finite element (FE) model of the SE(B) specimen. Good comparison was found between the surfaceT _ε ^* calculated from displacements extracted from the FE model and the surfaceT _ε ^* calculated from experimentally obtained displacements. The computedT _ε ^* integral was also observed to decrease as the crack front was traversed from the surface to the mid-plane of the specimen. Mid-planeT _ε ^* values tend to be approximately 10% of the surface values.     

<Emphasis Type="Italic">J</Emphasis><Subscript>2</Subscript> invariant relative orbits via differential correction algorithm

This paper describes a practical method for finding the invariant orbits in J ₂ relative dynamics. Working with the Hamiltonian model of the relative motion including the J ₂ perturbation, the effective differential correction algorithm for finding periodic orbits in three-body problem is extended to formation flying of Earth’s orbiters. Rather than using orbital elements, the analysis is done directly in physical space, which makes a direct connection with physical requirements. The asymptotic behavior of the invariant orbit is indicated by its stable and unstable manifolds. The period of the relative orbits is proved numerically to be slightly different from the ascending node period of the leader satellite, and a preliminary explanation for this phenomenon is presented. Then the compatibility between J ₂ invariant orbit and desired relative geometry is considered, and the design procedure for the initial values of the compatible configuration is proposed. The influences of measure errors on the invariant orbit are also investigated by the Monte–Carlo simulation. The project supported by the Innovation Foundation of Beihang University for Ph.D. Graduates, and the National Natural Science Foundation of China (60535010).     

HAMILTON OPERATORS AND HOMOTHETIC MOTIONS IN R^3

Quaternion is a division ring. It is shown that planes passing through the origin can be made a field with the quaternion product in R3. The Hamiltonian operators help us define the homothetic motions on these planes. New characterizations for these motions are investigated.     

MAXIMAL ELEMENTS FOR GB-MAJORIZED MAPPINGS IN PRODUCT G-CONVEX SPACES AND APPLICATIONS (Ⅰ)

A new family of set-valued mappings from a topological space into generalized convex spaces was introduced and studied. By using the continuous partition of unity theorem and Brouwer fixed point theorem, several existence theorems of maximal elements for the family of set-valued mappings were proved under noncompact setting of product generalized convex spaces. These theorems improve, unify and generalize many important results in recent literature. Contributed by DING Xie-ping Foundation items: the National Natural Science Foundation of China (19871059); the Natural Science Foundation of Education Department of Sichuan Province of China ([2000]25) Biography: DING Xie-ping (1938∼)