Lecture English Term Definition Chinese: Public

Transcription

1 Lecture English Term Definition Chinese: Public A Convert Change between two forms of measurements 变换 A Equilateral Triangle Triangle with equal sides and angles A FPS Units The American system of measurement. Uses ft. and lb., etc.. A Homogeneity When any group of two or more things have the same value 均匀性 A Homogeneous Properties are the same everywhere 均匀的 A Isotropic Properties are the same in all directions 各向同性 A Observation To look for important information A Right Triangle a triangle with one 90 degree corner A Rounding shortening a number, can use scientific notation A standard Scientific A number multiplied by 10 to a power of 3 Notation A SI Units The metric system of forces. Uses Newton, kilo, meter, etc.. 科学计数法 A Significant Figures Specifies the amount of digits used to express a number B Collinear When two objects or forces or vectors are on the same line 有效数字 B Magnitude The size or value of a measurement. 在同一直线上的 B Parallelogram A method to obtain the sum of two vectors by adding two vectors Construction together by joining their tails. B Resolution splitting a vector into two other vectors, or components 量 B Scalar Only has magnitude, not direction. Notated by an italic letter

2 B B Triangular Construction Vector Adding two vectors by joining the tail of one to the other's head Has magnitude and direction. Notated by an arrow over a bolded letter C Cartesian Unit Unit vectors that are parallel to the x, y and z axes 向量 ( 矢量 ) Vector, i, j and k C Cartesian Vector A vector defined by Cartesian coordinates C Coplanar When two objects, such as points or vectors, are on the same plane 笛卡儿矢量 C Coordinate Directional The angles between a vector and any axis 同一平面的 Angles C Directional Cosines Equal to Fx/F, Fy/F, and Fz/F 方向的坐标角度 C Directional Vector A unit vector pointing in the same direction of a vector 方向余弦 C Origin The intersection of the x, y, and z axes 方向向量 C Pythagorean theorem Fr=sqrt(frx^2+Fry^2), used to determine the sides of a triangle 原点 C Rectangular Components The x,y and z components of a vector C Resultant Force The sum of all forces in a system 直角坐标分量 标量 C Used to determine the direction of the axes: thumb=z, wrist=y, Right Hand Rule fingers=x C Unit Vector A vector with a length of 1 合力 C X-Y Cartesian Coordinate A system where each unit is of equal length 单位向量 system D Dead Load Load that is not likely to move. x-y 坐标系

3 D Distributed Load Load over an area or a line. 静荷重 D Live Load load that will move often 分布载重 D Load Equal to weight of an object 动荷载 D Position Vector Points from one point to another 负载 ( 荷载 ) D Forces or Loads distributed over an area or line, perpendicular to a Pressure surface 位置向量 D Forces or Loads distributed over an area or line and can be at Stress different angles 压强 D Weight How heavy an object is. Similar to load. 压力 E CP-Right Hand fingers(vector A) curl towards wrist(b), thumb is new vector(c). A 重力 Rule cross B = C E Gives a vector perpendicular to both vectors involved. Returns a Cross Product vector E Dot Product Returns a scalar used to calculate the angle between two vectors 向量积 ( 叉乘 ) E Normal Another word that means perpendicular 数量积 ( 点乘 ) E The part of a vector A along the vector B. Calculated by (A) dot Projection (unit vector of B) F Equilibrium of particles When the sum of forces and moment are balanced, therefore acceleration=0 F Free Body Drawing that shows all known and unknown forces, distances, Diagram (FBD) angles, or other information 平衡 F A point in space having no size, similar to a poin; and with mass, Particle but no size. 示力图 F A frictionless wheel that allows for the change of direction, or Pulley disbursement of a force 质点 F Spring Constant The ratio of the force to displacement affecting a spring 滑轮

4 F Spring Force F=k*s k is spring constant, s is stretch 弹簧系数 G Two parallel forces, equal and opposite in direction. Equal to a free Couple 弹簧弹力 vector G Couple Moment 1 equal to the distance between two forces times their magnitude 力偶 G Couple Moment 2 Will cause the same moment regardless of the forces' locations 力偶矩 G Free Vector Will apply the same effect regardless of location 力偶矩 G A turning effect produced by a force acting at a distance on an Moment object G Moment Arm The perpendicular distance between a force and the point of force 力矩 G Torque Same as Moment 力臂 G Vector Formulation Using cross product to obtain moment H Equivalent Replaces a complicated system with a simplified one having the System same external effect H Moment Resultant Sum of all the moments acting in a system H Wrench Replacement of all forces and moments with a single resultant force Replacement and moment that are parallel I Distributed Load Load over an area or along a line. Can be uniform or variable 扭矩矢量表达式等效系统合力矩 I Equal to either the length of the line of force, or the area under the Total Load 分布载重 area load I Uniformly A rectangular load evenly distributed over a length or area 总负载 ( 总荷载 ) Distributed Load I Water Pressure equal to 62.4 psf and is isotropic 均匀分布负载 J Redundant constraints when a body has too many supports and becomes statically indeterminate 水压

5 J Rigid Body a beam or object subjected to forces. See truss 虚约束 J Support A beam's support reactions to forces applied to it, and puts the Reactions beam in equilibrium 刚性体 J Support System Similar to Rigid Body 支承反力 ( 支反力 ) J Supports Can resist moment, x,y, and z forces, or a mix of the three. 支撑体系 K Compression - Truss Forces pointing towards the joint, are negative 支撑 K Frames Have members subjected to more than two forces 压缩 - 桁架 K Joints Intersection between two Members 框架 K Machines include moving parts that transmit forces and their effects 连接 ( 铰接 ) K Member Connect Joints in a Truss 机械 K Methods of Joints Calculate equilibrium one joint at a time, only 2 unknowns per joint 成员 ( 构件 ) K Methods of Sections Calculate equilibrium by dividing a truss with cuts 关节方法 ( 节点法 ) K Simple Truss a 2-D truss which begins as a triangular element 节段方法 ( 截面法 ) K Smooth Pins see joints 简单桁架 K Tension - Truss Forces pointing away from the joint, are positive K Truss A type of support system or beam K L Zero Force Member Bending Moment Subjected to zero forces and can be removed from calculations moment of a beam caused by external forces. Tension at bottom is positive 桁架 不受力杆件

6 L Cantilever Beam A beam with one end that is unsupported 弯曲力矩 L Internal Forces tension, Shear Force and Bending Moment in and along a beam 悬臂梁 L Max Tensile Stress stress resulting from tension L Maximum Shear Stress stress caused by area L Method of Sections Calculate the internal forces of a beam by making cuts L Neutral Axis Spot in a beam where tension=compression 内力 最大拉应力 最大剪应力 L Section A piece of a beam that can be analyzed for shear and moment 中性轴 L shear and moment Charts that show the magnitude of shear and moment along the diagrams beam 截面 L Shear Force Force perpendicular to a beam. CW is positive 剪力和弯矩图 L Strain deforming of a material resulting from external loading 剪力 L Stress intensity of internal force on or along a body 张力 M Applied Force Force applied to an object to cause movement 压力 M Dry Friction Friction between two solid bodies free from fluids or contaminants 作用力 M The resisting force acting between two materials that prevents Friction motion M The tan of this angle is equal to the coefficient of friction. Made Friction Angle with N and Fmax M Impending Just before an object moves, and static friction switches to kinetic Motion friction M Kinetic Friction Friction after movement has begun. Less than Static Friction 摩擦

7 M also know as Normal Force, the force applied on an object by the Reactive Force ground M Sliding When an object is not overbalanced and moves along a surface 动摩擦 M Static Friction Friction on a stationary object before it has began moving M Tipping When an object is overbalanced and falls 静摩擦 M Frictions when there is a fluid such as oil or grease between two Wet Friction bodies 倾卸台 ( 倾斜点 ) N Center of Gravity (CG) Point where the resultant weight is located. Found using the moment concept N Center of Mass Point where the resultant mass is located. Found using the moment (CM) concept 重心 N Centroid Geometric center of a body or system of bodies 质心 N Composite Body One body with multiple shapes, materials, or parts 几何中心 N Cylindrical Coordinates using r, z and theta instead of x, y, and z. 复合体 N Moment Concept Moment over weight 柱面坐标 O Area moment of inertia measure of how an area is distributed about axes O Moments of Inertia Resistance of rotating bodies to potential changes in their rotation O Parallel Axis relates the moment of inertia around a shapes centroid to the axis of Theorem interest O helps calculate the axis that yields the maximum or minimum Product of Inertia moment of inertia O Radius of the distribution of cross-sectional area in a beam around its central Gyration axis O Simpson's Rule A way to calculate area without using integrals 力矩的概念面积惯性矩转动惯量平行移轴定理惯性积

8 回转半径 all Objectives A goal or a desired outcome 辛普森积分法 Pre-requisite Stuff needed before starting 2-D On a flat plane. In two dimensions Stud A board used in supporting a wall 3-D In a three dimensional space. Force an influence on a body to cause movement or stress