Ball Impact Research Articles

Numerical investigation of ice plate fractures upon rigid ball impact

The fracture process and breaking capability of ice cover impacted by high-speed projectiles before underwater explosion is an urgent subject of scientific research in ice engineering applications. This paper presents the results of numerical simulations of the dynamic fracture behaviour induced by the impact of a small spherical projectile on an ice plate. The proposed 3D rate-dependent peridynamics model is validated by the dynamic ring Brazilian disc testing of ice specimens. Good agreements between the present model and the previous experiments are obtained in ice breaking processes and damage patterns of thin, medium and thick ice plates. Several cases are analysed and discussed in terms of various impact velocities, ice thicknesses, and boundary constraint conditions. The simulations identify detailed fracturing characteristics that are not observed in experiments, including the sequence and shape of crack propagation in a short time interval, the crater formation and the damage evolution along the thickness direction. The proposed peridynamics computational model provides new understanding of the potential of using penetrator–ice block impact tests to observe the evolution of complex brittle damage and reveal the failure mechanism.

Transforming tree topping waste into flooring: a study on the production and evaluation of oriented strand board finish using urban and garden residues.

Oriented strand board (OSB) has become a popular building material for residential construction, but little research has been conducted on its use as a finish floor material. The study investigated the quality and performance of OSB as an alternative to traditional engineered wood products for finish floors. Four types of OSB finish floors using a mixture of garden and urban tree toppings were produced and evaluated, along with different types and levels of resin and mat moisture content. The finish floor panels were subjected to a battery of tests, including concentrated loading, indentation, falling ball impact resistance, abrasion resistance, and surface wettability. The findings showed that urea formaldehyde resin with garden tree toppings performed best in floor surface indentation, abrasion resistance, and falling ball indentation. The phenol formaldehyde resin with garden tree toppings, on the other hand, showed less moisture absorption and swelling during surface wetting tests and better resistance to force application in the concentrated loading test. Our qualitative comparison revealed that OSB finish floor production using 100% garden tree topping strands and 12% urea formaldehyde resin, along with 14% mat moisture content, produced the best results. The study provides valuable insights into the potential use of OSB as a sustainable and cost-effective finish floor material, using waste materials from urban and garden tree toppings.

From Harvest to Market: Non-Destructive Bruise Detection in Kiwifruit Using Convolutional Neural Networks and Hyperspectral Imaging

Fruit is often bruised during picking, transportation, and packaging, which is an important post-harvest issue especially when dealing with fresh fruit. This paper is aimed at the early, automatic, and non-destructive ternary (three-class) detection and classification of bruises in kiwifruit based on local spatio-spectral near-infrared (NIR) hyperspectral (HSI) imaging. For this purpose, kiwifruit samples were hand-picked under two ripening stages, either one week (7 days) before optimal ripening (unripe) or at the optimal ripening time instant (ripe). A total of 408 kiwi fruit, i.e., 204 kiwifruits for the ripe stage and 204 kiwifruit for the unripe stage, were harvested. For each stage, three classes were considered (68 samples per class). First, 136 HSI images of all undamaged (healthy) fruit samples, under the two different ripening categories (either unripe or ripe) were acquired. Next, bruising was artificially induced on the 272 fruits under the impact of a metal ball to generate the corresponding bruised fruit HSI image samples. Then, the HSI images of all bruised fruit samples were captured either 8 (Bruised-1) or 16 h (Bruised-2) after the damage was produced, generating a grand total of 408 HSI kiwifruit imaging samples. Automatic 3D-convolutional neural network (3D-CNN) and 2D-CNN classifiers based on PreActResNet and GoogLeNet models were used to analyze the HSI input data. The results showed that the detection of bruising conditions in the case of the unripe fruit is a bit easier than that for its ripe counterpart. The correct classification rate (CCR) of 3D-CNN-PreActResNet and 3D-CNN-GoogLeNet for unripe fruit was 98% and 96%, respectively, over the test set. At the same time, the CCRs of 3D-CNN-PreActResNet and 3D-CNN-GoogLeNet for ripe fruit were both 86%, computed over the test set. On the other hand, the CCRs of 2D-CNN-PreActResNet and 2D-CNN-GoogLeNet for unripe fruit were 96 and 95%, while for ripe fruit, the CCRs were 91% and 98%, respectively, computed over the test set, implying that early detection of the bruising area on HSI imaging was consistently more accurate in the unripe fruit case as compared to its ripe counterpart, with an exception made for the 2D-CNN GoogLeNet classifier which showed opposite behavior.

Copper Wire Bonding: A Review.

This paper provides a comprehensive review on copper (Cu) wire bonding. Firstly, it introduces the common types of Cu wire available in the market, including bare Cu wire, coated Cu wire, insulated Cu wire, and alloyed Cu wire. For each type, their characteristics and application areas are discussed. Additionally, we provide detailed insights into the impact of Free Air Ball (FAB) morphology on bonding reliability, including its effect on bond strength and formation mechanisms. Next, the reliability of Cu wire bonding is analyzed, with a focus on the impact of intermetallic compounds and corrosion on bonding reliability. Specifically, the formation, growth, and stability of intermetallic compounds at bonding interfaces are discussed, and their effects on bonding strength and reliability are evaluated. The detrimental mechanisms of corrosion on Cu wire bonding and corrosion inhibition methods are also analyzed. Subsequently, the applications of simulation in Cu wire bonding are presented, including finite element analysis and molecular dynamics simulations, which provide important tools for a deeper understanding of the bonding process and failure mechanisms. Finally, the current development status of Cu wire bonding is summarized, and future research directions are discussed.

Finite Element Simulation of a Passive Damper System Using Contact Algorithm

Impact dampers are passive devices wherein a moving mass impacts with the primary structure. The vibrations caused due to these impacts are random in nature. During these impacts, exchange of momentum occurs resulting in dissipation of energy. Here, theoretical model of an impact damper system is modelled as MDOF system using Hertzian contact algorithm. Numerical simulation of the above problem was created using ANSYS Finite Element Analysis (FEA) package. Augmented Lagrangian method with Newmark’s time integration scheme is used for simulations. The problem being studied is highly nonlinear in nature with contacts being established during impact. Normal contact force generated due to impact of ball are used to get the transient response of the system.
 Detailed study was carried out with various mass ratio at low frequency and high amplitudes of excitation. Not much studies have been carried out earlier using MDOF systems with contact algorithm. Above modelling and simulation study was helpful to visualise and accurately capture the transient movement of the impact mass within the confined space.

Mechanochemical Reactions from Individual Impacts to Global Transformation Kinetics

AbstractTypically induced by the mechanical processing of powders in ball mills, mechanochemical transformations are considered to result from the application of mechanical force to solid reactants. However, the undeniable deep connection between the dynamic compaction of powders during impacts and the overall transformation degree has yet to be disclosed. In the present work, we show that the square planar bis(dibenzoylmethanato)NiII coordination compound undergoes trimerization when its powder experiences even a single ball impact. Based on systematic experiments with individual ball impacts and analysis by Raman spectroscopy, we provide here quantitative mapping of the transformation in the powder compact and deduce bulk reaction kinetics from multiple individual impacts.

Mechanochemical reactions from individual impacts to global transformation kinetics.

Typically induced by the mechanical processing of powders in ball mills, mechanochemical transformations are considered to occur as a result of the application of mechanical force to solid reagents. Nevertheless, such claim has remained vague so far and the undeniable deep connection between the dynamic compaction of powders during impacts and the overall transformation degree has yet to be fully disclosed. In the present work, we show that the square planar bis(dibenzoylmethanato)Ni(II) coordination compound undergoes trimerization when its powder experiences even a single ball impact. Based on systematic experiments with individual ball impacts and analysis by Raman spectroscopy, we provide here quantitative mapping of the transformation in the powder compact and deduce bulk reaction kinetics from multiple individual impacts.

Independent friction-restitution description of billiard ball collisions

The oblique impact of a cue ball moving on a horizontal surface with an arbitrary spin on an object ball at rest is described using the independent friction-restitution modeling of impact. The model yields theoretical expressions for the post-collision linear and angular velocities in terms of ‘constant’ coefficients of normal restitution, tangential restitution, and friction for both stick and slip regimes of impact. The model also predicts the post-impact velocities reached by the balls when, as a result of friction with the supporting surface, the pure rolling motion is established. Theoretical predictions are in satisfactory agreement with experimental data for collisions between regulation billiard balls, steel, brass, and rubber spheres.

Dynamic adjustment of submaximal effort soccer side-foot kicks

ABSTRACT We aimed to illustrate kicking leg dynamics during submaximal effort soccer side-foot kicks. Side-foot kicks with three effort levels (50, 75 and 100% effort levels based on maximal effort) of eight male university soccer players were captured (500 Hz) while initial ball velocities were monitored simultaneously. Systematic regulation in joint kinetics (angular impulses) was clearly demonstrated for hip flexion and knee extension moments thereby supporting the interpretation that the final foot velocity is controlled in a context of a planar, sequential segmental system. Out of the thigh-shank plane motion (hip external rotation moment) was also found to be systematically adjusted. Kinematic contributions of knee extension angular velocity to the final foot velocity increased significantly in the maximal effort while that of hip external rotation reduced significantly, coinciding with a more straightforward approach-run. The adjustable range of the foot-ball interaction was found to be rather smaller in side-foot kicks. However, significantly smaller ball/foot velocity ratios in the two submaximal conditions suggested ankle joint fixation was manipulated towards ball impact. Players and coaches ought to recognise that the intensities of side-foot kicks were regulated by the motions within and without the thigh-shank plane alongside several kinematic changes.

DIFFERENCES IN KINEMATIC PARAMETERS BETWEEN FIRST AND SECOND SERVES IN TENNIS BY ELITE PLAYERS OF THE GERMAN LEAGUE

The primary goal of this research was to determine the differences in kinematic parameters between the first and second serves in tennis among the elite players of the German league. The sample of respondents in this research consisted of 30 elite male senior players of the German League who have "Leistungklasse" from 1 to 7. The kinematic parameters that were analyzed are: Height of ball impact (KPVUL), Racket speed (KPBRE), Ball speed (KPBLO), The angle at the elbow joint of the arm that hits the ball (KPULZ), Oscillation of the vertical projection of the center of gravity of the body (KPOVP), Jump height (KPVSK), Ball launch height (KPVIL), The point of contact between the ball and the racket "sweetspot" (KPMLR), Ball rotation "Top spin" (KPRLO). The video recording required for kinematic analysis was acquired with two Casio EX-F1 digital cameras at a frequency of 200 images per second. The camera was placed at an angle of 900 in relation to the recording plane, and they were at a distance of 10 m. Space calibration was performed with the help of a calibration frame (200 x 200 cm). We have installed Zepp Tennis Smart Sensor 2.0 in the handle of the Wilson Pro Staff RF97 Autograph racket, using the Zepp Tennis application software. "Kinovea" software was used for service analysis and obtaining kinematic parameters from video recordings. By analyzing the results of the T-test for independent samples, it can be seen that there are statistically significant differences in five of the nine analyzed kinematic parameters : KPBRE – kinematic parameter of racket speed (Sig.=.000), KPBLO – kinematic parameter of ball speed (Sig.=.000), KPULZ – kinematic parameter angle in the elbow joint (Sig.=.000), KPMLR – kinematic parameter point of contact between the ball and the racket (Sig.=.000), as well as a variable KPRLO – kinematic parameter of ball rotation (Sig.=.000). Larger numeric values in variables: KPVUL – kinematic parameter ball impact height, KPOVP – kinematic parameter of oscillation of the vertical projection of the center of gravity of the body, KPVSK – kinematic parameter jump height and KPVIL – kinematic parameter ball impact height, show a difference but it is not enough to be statistically different. Key words: tennis, kinematic analysis, racket speed, Zepp sensor

Dynamic mechanical properties, interface structure evolution and deformation behaviors of PVA-carbon fiber reinforced concrete with negative Poisson’s ratio design

Based on the advantages of negative Poisson's ratio (NPR) materials in controlling deformation and absorbing energy, this paper combines NPR design with the preparation of fiber reinforced concrete (FRC) to optimize the anti-dynamic load performance of FRC. In this paper, a helical auxetic yarn (Hay) with NPR effect is obtained by wrapping carbon fiber (CF) on polyvinyl alcohol fiber (PVAF) at a certain angle, and it is mixed into concrete in different forms to obtain auxetic fiber concrete. In order to explore the influence of auxetic fiber on the anti-dynamic load performance of concrete, split Hopkinson pressure bar (SHPB) test and dropping ball impact test are carried out on different FRC. The impact resistance of FRC under different impact velocities is tested, and the impact resistance behavior of FRC is analyzed by digital speckle correlation method (DSCM). The results show that in SHPB test, the anti-impact strength of the layered auxetic fiber concrete is 19.1 % higher than that of the plain concrete (PC), and its fracture energy is increased by 25.8 %. In the dropping ball impact test, its fracture energy is 5 ∼ 9 times that of PC. In addition, the results of scanning electron microscopy (SEM) and DSCM test show that the incorporation of auxetic fiber has a positive effect on improving the generation and development of internal cracks in concrete, which is expected to provide a reference for the application of NPR materials in explosion resistance, penetration resistance and impact resistance of building structures.

High rate response of elastomeric coatings for wind turbine blade erosion protection evaluated through impact tests and numerical models

The high strain rate (above ∼104/s) behavior of an elastomer is characterized using low strain rate (below ∼101/s) dynamic mechanical thermal analysis and time–temperature superposition. This approach is validated using high strain rate ball impact experiments and finite element predictions of ball deformations and rebound speeds. The ball impact experiments are performed by shooting 6 mm rubber balls with a controlled impact speed of 50–170 m/s at steel and polyurethane targets. An explicit axisymmetric finite element model of the ball impact experiment is established in the commercial code Abaqus. The validated material properties are used to model the viscously dissipated energy and the corresponding temperature increase in the polyurethane target. The region with the largest dissipated energy in the target material is predicted to be in a ring around the impact center with a radius of approximately 1 mm. This region corresponds well to locations of early damage initiation observed in the impact fatigue experiments for similar materials. The predictions are confirmed by the observed temperature distributions using thermal camera imaging of the rubber ball impact experiment. The experimental setup was developed for impact fatigue testing of anti-erosion coatings for the leading-edges of wind turbine blades.

Predictors of Ball Velocity in the Sitting Volleyball Serve: A Causal Analysis.

This study explored the performance of the Sitting Volleyball serve by investigating the causal factors associated with ball velocity. Thirty-seven athletes underwent anthropometry and strength assessment and performed ten successful maximal effort serves. Ball velocity was measured using a sports radar gun. The hip, shoulder, elbow and wrist angles at the instant of ball impact as well as the height of ball impact were estimated through two-dimensional motion analysis. The causal relationships between variables were described through a linear Structural Equation Model and a Directed Acyclic Graph. Results showed that a smaller hip angle determines a greater shoulder angle, which in turn causes a greater elbow angle. A more open elbow angle together with a greater vertical reach allowed for a greater height of ball impact. Finally, increased height of ball impact along with greater abdominal strength are beneficial for higher ball velocity. These results underlined that the Sitting Volleyball serve is a multifactorial stroke involving anthropometric, technical and strength factors and suggest that athletes should improve their abdominal strength and master the technique necessary to perform the serve with the shoulder and the elbow joints fully extended in order to produce the greatest possible impact on the ball.

Quantifying the efficacy of protective eyewear in pediatric soccer-induced retinal injury

Ocular injury is common in children playing sports. Sports-related eye injuries, if severe enough, can lead to permanent vision impairment. Soccer, the most popular sport in the world, is a sport in which players rarely use protective eyewear. The purpose of this study was to determine how eye injuries are induced by a soccer ball impact and to evaluate whether eye protection influences the effects of impact. A finite element (FE) computer simulation was used to simulate soccer ball trauma on a model of the eye with and without eye protection. Protective eyewear of different materials (polycarbonate and acrylic) was modeled to investigate the optimal medium for eye protection. Stress and strain experienced by the eyeball was quantified by the FE computer simulation in each model. Protective eyewear was found to be effective in lowering ocular stress and strain by absorbing and redirecting energy from the ball. Compared to the unprotected eye model, polycarbonate eyewear reduced the average stress the retina experienced by 61%, whereas the acrylic model reduced the average stress by 40%. Polycarbonate and acrylic eyewear also reduced the maximum strain experienced by the retina by 69% and 47%, respectively, reducing the severity of deformations of the eye on impact. These findings suggest that wearing protective eyewear, especially when made of polycarbonate, can be an effective means of reducing injury-inducing retinal stress. The use of eye protection is thus recommended for pediatric patients participating in soccer.

Numerical simulation using in the preparation process of micron‐sized silica–aluminium composite powders by high‐energy alloying: Building visualisation and guiding preparation

AbstractSilica‐aluminium composite powders are important precursors for the preparation of sealant coatings by supersonic flame spraying. Micron‐scale silica‐aluminium composite powders can be prepared using a planetary ball mill, but powder agglomeration often leads to composite failure. Using relevant modelling software to build the 3D modelling of the ball mill jar, which based on the discrete element method, using the Hertz–Mindlin contact model and after specifying the simulation boundary conditions, the ball mill process was simulated and analysed. Visualise the influence of important process parameters such as frequency, size and diameter of milling balls and ball‐to‐powder weight ratio, and systematically analyse the microscopic morphology and composite condition of the agglomerated and dispersed powders. The results show that the ball motion during the ball milling process is mainly divided into three representative types: ball–ball impact, ball crushing motion against the jar wall and ball–wall impact. The energy transfer efficiency of the milling balls to the powder system is highest when the ratio of the three types of motion is uniform. SEM images and EDS spectra showed that the aluminium powder was sufficiently crushed, with an average particle size below 1 μm. The aluminium powder was uniformly distributed on the surface of the silicon powder, and the particle size of the composite silicon aggregates was sufficiently reduced.

Photochromic safety-glass based on polyurethane interlayer film blend with perovskite quantum dot

In recent years, photochromic glass has been widely used in smart windows, depending on its thermal insulation, concealment and intelligent controllability. However, the safety requirements of photochromic glass are still one of the problems to be solved in practical applications. In this work, a photochromic composite film based on polyurethane/perovskite quantum dots (HPU) has been got by casting blending extrusion process. Then laminated safety glass based on the HPU intermediate films are constructed by hot pressing process, the glass of which shall be coated with a layer of acrylate hot-melt adhesive (PA) before use. Under ultraviolet light, it can be displayed in green from colorless within 0.5 s, and transmittance of laminated glass is almost the same as that of single-layer glass under natural light. The safety of laminated glass based on the glass/PA/HPU/PA/glass structure is evaluated by falling ball impact test. There are no glass fragments falling off and splashing when they are impacted by a 50 g of steel ball falling freely from a height of 1 m. The excellent environmental stabilities have been confirmed by fluorescence spectrum tracking. The intelligent photochromic safety-glass mentioned in this work has great application potential in the fields of building windows, automotives and optical devices.

Optimal Mixture of Materials and Condition in Producing Flat Glasses for Automobile Windscreens in Nigeria

The selection of materials is an essential element for engineering designers. This study investigated the optimal mixture of materials and condition in producing flat glasses for automobile windscreens in Nigeria. To achieve this, 10 pairs of compositions of material mixtures and cullet (broken glasses) were used. The standard material mixture (80/20 wt. % of material mix/cullet) from the local industry was modified to have batches of up to 60/40 wt. % material mix/cullet. These material mixtures were used to produce flat glasses by adopting procedures of industrial float glass process of Pilkington Brothers in variable conditions of annealing temperature and time. The average density of each pair of flat glass was measured using water displacement method, and each pair was later laminated to produce a total of 10 automobile windscreens. The windscreens were subjected to 2.25kg drop ball impact test from a height of 4m at 900. The study revealed that the density of the flat glass produced was significantly (p< 0.01) related to squared composition (wt. %) of cullet (R2=97.65%). The highest and lowest densities of 2.23g/cm3 and 1.95g/cm3 were obtained at cullet inclusions of 40 wt. % and 20 wt. % respectively at constant annealing temperature (5500C) and time (60 min). The optimal batch obtained composed of 40 wt. % cullet inclusion, annealed at 5000C for 50 minutes. Increased cullet composition was found to reduce the melting temperature of the batch mixture and fractured characteristics of the windscreens produced. Employing this design in the windscreens manufacturing industry saves production cost, facilitates a competitive market, enhance the quality of windscreens, reduce emissions and curb environmental degradation.

Experimental Study on the Vibration Reduction Performance of the Spindle Rotor of a Rubbing Machine Based on Aluminium Foam Material

Larger vibration and noise often exist in agricultural machinery due to the harsh working environment and high power. The rubbing machine is one of the indispensable pieces of equipment in the agriculture and livestock industry, and it is affected by the vibration of large constraints on its promotion and use. To reduce the vibration of the rubbing machine, the vibration characteristics of the spindle rotor were first analysed by modal simulation, thus determining the larger contributions to the spindle rotor vibration. Second, aluminium foam material was installed in the large deformation part of the spindle rotor. Its vibration reduction and energy absorption characteristics were used to optimise the vibration reduction design by increasing the damping. Third, a steel ball impact test was conducted to analyse the vibration characteristics of the optimised spindle rotor. The results show that the maximum impact accelerations were reduced by 28.4% and 64.75% in the axial and radial directions, respectively, and the impact energies were reduced by 67.3% and 90.65% in the axial and radial directions within 2 s of impact collision, respectively, indicating that the optimised spindle rotor damping increased significantly. In addition, the vibration reduction effect of the optimised rubbing machine was verified by a bench test. By measuring the change degree of the static component of the spindle rotor vibration, the axial, radial, and vertical vibrations of the spindle rotor were improved by 5.78%, 10.32%, and 23.96%, respectively. Therefore, optimising the spindle rotor with aluminium foam material can reduce the vibration generated during the impact of the material on the spindle rotor. The rubbing machine’s vibration, damping, and energy absorption were also realised in real working conditions.

A Systematic Review of Spatial Differences of the Ball Impact within the Serve Type at Professional and Junior Tennis Players

Since the flat serve (FS) minimizes the ball spin and kick serve (KS) combined topspin and sidespin, this systematic review aimed to explore the ball impact location (BI) within the FS and KS at the professional men, junior men, and women tennis players. The PRISMA guideline was used, and the original articles were searched in Scopus, Web of Science, and PubMed. The means and standard deviations computed from the distance of BI from the origin within the FS and KS on the x, y, and z axes (global coordinate system) were normalized by the participants’ height and weighted by the number of participants in one-way ANOVA. Ten articles with a pooled sample of 133 males and 51 females aged 11–25 were included. The professional men had more stable BI on the x-axis within the FS by 56% (p < 0.001), within the KS by 58% (p < 0.001), and on the y-axis within the KS by 90% (p < 0.001) than junior men. The professional and junior men had the BI more leftwards from the origin on the x-axis within the KS by 188% (p < 0.001) and 88% (p < 0.001), respectively than within the FS.

Kinematics analysis of tennis forehand strokes in different directions for the elite female college tennis players

<p>目的：探討優秀大專女子網球選手執行正拍直線球、對角球與閃正拍外角球之動作分期時間、軀幹旋轉特徵與擊球位置之動作技術差異。方法：以 9 名台灣大專甲組之女子網球選手為研究對象，透過 Motion 動作分析系統與十台紅外線高速攝影機 (取樣頻率為 200 Hz) 記錄網球正拍擊球執行直線球、對角球、閃正拍外角球之動作技術，以相依樣本單因子變異數分析進行統計分析。結果：在擊球動作期別上僅在加速期達顯著差異且對角球大於閃正拍球；軀幹與站姿軸的運動學參數中，除了肩軸沒有達顯著差異外，球拍長軸與底線夾角、髖軸、站姿軸設定皆達顯著差異；此外，擊球點與肩膀的前後距離以及髖部的前後、左右距離的相對位置皆達顯著差異。結論：當球員針對不同方向擊球時，球拍開始向前加速的加速期是影響方向的關鍵時期。在擊球瞬間肩部旋轉並不是影響擊球方向的主要因子，且選手在執行閃正拍外角擊球會採取較大幅度的軀幹旋轉策略進行調節。此外，擊球點與身體的相對位置關係，不論肩部或是髖部的前後距離是影響擊球方向的關鍵因素，在左右側的擊球點位置閃正拍相較於直線與對角球會更靠近軀幹。本研究結果希望讓教練與選手了解，在執行不同擊球方向或閃正拍外角球策略時，身體軀幹特徵之異同，且可以作為球員在比賽中預判對手擊球策略時的參考因素之一。</p> <p> </p><p>Purpose: This study identified and compared the kinematic difference of each phase, trunk, and stance when balls were hit cross-court, down-the-line, and inside-out forehand for the elite college female tennis players. Methods: Nine female tennis players from Taiwan college Division 1 players were recorded using a ten-cameras with motion analysis system (200 Hz). The techniques of hit down-the-line, cross-court, and inside-out forehand were recorded, and statistically analyzed by one-way ANOVA with repeated measured. Results: The only significant difference was found in the acceleration phase and the cross-court was larger than inside-out forehand. For the kinematic parameters, the angle of the long axis of the racket, hip alignment, stance alignment were statistically different. In addition, in the relative positions of the contact point, there was no significant difference in vertical height on shoulder and hip, and the shoulder was only significant in the hitting direction, but the hip was significantly different in the hitting direction and the side direction. Conclusion: In the situation of different directions, the acceleration phase when the racket starts to accelerate forward, is the key phase that affects the direction. At impact, shoulder alignment angle is not the main factor affecting the direction of the shot. The players will adopt more trunk rotation when performing inside-out forehand shots. In addition, the relative position of ball impact, the distance between the contact point with shoulder and hip on the front direction is the key factor. On the side direction, the inside-out forehand is closer to the trunk than the cross-court and down-the-line shots. This study provides coaches and players with strategies of different directions and inside-out forehand. The body characteristics can be a reference for players to predict the opponent’s strategy in the matches.</p> <p> </p>