Bottom Rail Research Articles

Stress Analysis and Structural Improvement of LNG Tank Container Frames under Impact from Railway Transport Vehicles

As the stress of the frame, especially the bottom side rail supports and bottom inclined supports, of a traditional LNG tank container could be significantly greater than its allowable stress, and the container cannot meet the strength requirement of the specification when it is impacted by a transport vehicle during railway transportation, three improved frame structures were suggested, which removed or changed the side rails or bottom inclined supports; the stress and deformation of these improved frames and the tank container were analyzed using the finite element method under the impact test. The results show that all three improved frames can meet the strength requirement, i.e., the maximum Mises stress is less than the allowable stress and the deformation requirement of the diagonal length difference is less than the allowable value, meaning that the tank containers with improved frames can pass the impact test. Moreover, for the FRP support rings and impact side heads, although the maximum values are different, they are still less than the respective allowable stresses. In addition, the maximum value of the middle cross section of the outer vessel in the direction of gravity does not increase with the change in the frame, and the deformation of the outer vessel remains within the elastic range. Therefore, the improvements of the frames have little effect on the stress and deformation of the other components of the tank container, in particular, the inner vessel and outer vessel. Compared to the frame of the traditional tank container, removing the side rails partially or completely can reduce the weight of the frame by 17.99% and 38.34%, respectively, greatly reducing manufacturing and transportation costs. It can also reduce the maximum Mises stress by 38.89% and 39.24% and the maximum diagonal difference by 57.95% and 61.16%.

ALAT PROYEK MIKRO KONTROL PENGHAPUS PAPAN TULIS OTOMATIS MENGGUNAKAN REMOTE BERBASIS ARDUINO

The development of automation technology on blackboard erasers can increase the level of hygiene and health, because with an automation system the activity of erasing the blackboard can be carried out automatically without inhaling marker ink which has an impact on health and does not dirty hands. The purpose and working mechanism of making an automatic blackboard eraser using a remote and Arduino. The method of designing an automatic whiteboard eraser is made using an arduino uno as a microcontroller and an infrared remote that controls a stepper motor to drive the eraser. The assembly of the blackboard eraser mechanism is done by preparing a blackboard prototype that has been mounted on an iron frame. Then, install the top rail and bottom rail. Followed by installing the upper and lower wheels on the upper and lower rails that have been glued to the eraser clamp. The results of the design of an automatic whiteboard eraser based on Arduino Uno, can facilitate teachers and students in the learning process. The conclusion of this design is that the automatic whiteboard eraser can work according to the program that has been entered into the arduino uno and is controlled by an infrared remote and the whiteboard eraser working mechanism functions properly to erase the marker ink on the blackboard with a power of 26.67 watts

Research on the three-dimensional detection system of the rail full profile

To solve the problem of slow speed, low precision and low efficiency of manual measurement in the current inspection of rail. Based on the non-contact laser profilers, a three-dimensional detection system of the full profile of rail is proposed by using the integrated combination of four laser profilers. The top straightness of the rail is detected by two-point connection method and the bottom distortion of the rail is detected by the common-plane method. After field testing, the machine measurement accuracy of the rail height, rail head width, rail bottom width and rail waist width in both rail head and tail are 0.039, 0.037, 0.029, 0.036mm and 0.047, 0.037, 0.039, 0.042mm respectively; The distortion are 0.035 and 0.039mm respectively. Experiments show that the system can complete the measurement of rail efficiently and steadily, and improve the speed, accuracy and efficiency of measurement.

New recommendations for self-locking barriers to reduce skin injuries in dairy cows

The design of self-locking barriers can affect cows’ skin injuries and impair welfare. This study aimed to propose and refine recommendations, expressed relatively to the cows’ dimensions, for self-locking barrier design to reduce risks for skin injuries on the neck/shoulder/back and on carpus of dairy cows. We recorded individual body dimensions and the dimensions of self-locking barriers (e.g. top rail height) and assessed skin injuries on 3801 cows from 131 loose-housing dairy farms. We explored the significant associations between presence/absence of skin injuries and self-locking barrier dimensions using weighted multivariable logistic regression, taking into account the diversity of feeding barriers within each farm. The robustness of the models was assessed by cross-validation. Cows had skin injuries mainly on the neck/shoulder/back (29.0%) and, to a lesser extent, on the carpus (14.0%). The final multivariable logistic regression models comprised 13 factors for skin injuries on the neck/shoulder/back, and 11 factors for skin injuries on the carpus. Skin injuries were significantly reduced when the self-locking barriers were inclined (neck/shoulder/back) and when the cows used a feeding table (i.e. flat) instead of a feeding manger or cribs (i.e. hollow) (carpus). A top rail height >1.05 × cow height (measured at withers) was significantly associated with fewer skin injuries on the neck/shoulder/back and on carpus. Skin injuries on the neck/shoulder/back and carpus were significantly reduced when the bottom rail was on the food side relative to the wall, and at a height <0.39 of cow height. Skin injuries were significantly less frequent when the separation wall had no sharp edges on the food side (neck/shoulder/back), was >0.4 of cow height (carpus), was thinner than 15 cm (neck/shoulder/back and carpus) and when the height of the feeding step was 0.04 to 0.1 of cow height (neck/shoulder/back) and the length of the feeding step was <0.2 of cow length (carpus). A headlock articulation nut positioned between 0.62 and 0.78 of cow height significantly reduced skin injuries on the neck/shoulder/back. Here, by combining the diversity of on-farm self-locking barriers and their respective dimensions, we were able to refine the International Commission of Agricultural and Biosystems Engineering recommendations for self-locking barrier design and to propose new ones. This information now needs to be confirmed on other datasets, but can already help farmers and dairy industry stakeholders improve the design of self-locking barriers to improve dairy cow welfare.

Do International Commission of Agricultural and Biosystems Engineering (CIGR) dimension recommendations for loose housing of cows improve animal welfare?

Design of cubicles and self-locking barriers can affect cow skin alterations, lameness, and dirtiness. We investigated whether the International Commission of Agricultural and Biosystems Engineering (CIGR, Gainesville, FL)-recommended cattle housing design and dimensions actually improve cow welfare. We recorded individual cow body dimensions and assessed skin alterations, dirtiness, and lameness on 3,841 cows from 131 loose housing dairy farms (76 farms with cubicles and 55 straw-yard systems). We recorded the dimensions of cubicles (e.g., width, length, and so on) and of the self-locking barrier (e.g., top rail height and so on) for each farm. We then compared whether these dimensions would match with the individual cow body dimensions and whether compliance was associated with the occurrence of skin alterations, lameness, and dirtiness. Most cows (69.2%) had at least one skin alteration, on the tarsus (41.2%); neck, shoulder, or back (28.2%); hindquarters (22.0%); carpus (21.2%); and flank, side, or udder (11.6%). Lameness prevalence reached 17.9%. Most cows (83.1%) were scored dirty in at least one body region, mainly on the lower hind legs including hocks (81.4%), hindquarters (41.8%), and udder (21.0%). Cubicle recommendations were mostly met for cubicle resting length (75.9% of cubicles) and neck rail distance (NRD, 60.7%) but less so for overall cubicle length (CL, 38.8%), cubicle width (CW, 30.9%), neck rail height (NRH, 22.5%), head space (HS, 15.8%), partition zone for controlling lying position (ii zone, 15.7%), head and lunging space (HLS, 10.6%), partition head zone (i zone, 9.4%), and partition zone for pelvis freedom (iii zone, 6.0%). Compliance with design recommendations was associated with fewer skin alterations on neck (recommendation met for CW, CL, HS, and NRD and i zone), hindquarters (CW, CL, NRD), tarsus (CW, i and ii zones), and carpus (CW, HS, i and ii zones); less lameness (CW, NRH, i zone); and less dirtiness on the hindquarters (CW, HLS, NRD), lower hind legs (iii zone), and udder (CW, CL, HLS, NRD). Compliance with recommended i zone and ii zone design was associated with less injury and lameness but more dirtiness, whereas the opposite was true for the iii zone. Self-locking barrier recommendations were mostly met for bottom rail height (68.2%), separation wall width (SWW, 68.3%), and top rail height (TRH, 56.9%) and less often met for separation wall height (36.3%) and height difference between feeding floor and walking alley (26.5%). Risk for skin alterations on carpus and neck only decreased when SWW and TRH met recommendations. In conclusion, compliance with CIGR recommendations for some cubicle dimensions and neck rail position was associated with lower risk for cow welfare. However, the CIGR recommendations on cubicle partitions and self-locking barriers still leave welfare at risk and so need to be refined through further research with close observation of cow lying and feeding behavior.

Long-span semi-rigid cable barriers designed for high-impact severity satisfying the small car impact speed of 160 km/h

This study attempts to develop a semi-rigid barrier that produces a dynamic lateral displacement of approximately 0.8 m for the large vehicle impact energy of 261.4 kJ (14-ton truck – 85 km/h – 15°) and satisfies the small car impact condition of 1.3 tons – 160 km/h – 20°. Through extensive finite element analyses for various alternatives, it was investigated that a cable barrier could play a role of a semi-rigid barrier and satisfied the target performance when it, into which the initial pre-stressed force of 1900 kN was introduced, employed strong posts with a post spacing of 60 m. The occupant safety of this semi-rigid cable barrier is improved when the post spacing is increased but the initial pre-stressed force of the cables and cable anchor systems had to be increased to maintain the same working width. Due to the flexible characteristics of cable barriers with long spans, the semi-rigid cable barrier showed a possibility that it could accommodate small car impact velocities higher than 160 km/h. However, the semi-rigid cable barrier also revealed a vulnerability for large vehicle impacts as its bottom rail might rotate if the installation height was not enough to accommodate the deflection of cables. The final design of the long-span strong-post semi-rigid cable barrier was verified through full-scale vehicle crash tests.

On the anchoring of timber walls to foundations: available strategies to prevent wood deterioration and on-site installation problems

Experts are aware that the critical and until now unsolved problem of timber wall buildings lies in proper anchoring of the structure to foundations. Geometric inaccuracies and discrepancies between the concrete surface and the timber structure often lead to incorrect alignment of walls, which is normally solved with provisional and inaccurate solutions, in contrast with prefabrication. However, the most important issue is the compromised durability of timber due to rising dampness and fungicide attack, which are a result of inaccurate waterproofing as moisture is absorbed and trapped at the wall base. Difficulties in restoring such damages arise together with maintenance costs of the structures. This work provides an overview on the crucial problems that affect the anchoring of timber structures to foundations. Disadvantages of traditional techniques are presented and critically discussed. An innovative aluminium bottom rail designed for Cross-Laminated Timber, light-frame and Blockhaus technologies is presented, evidencing main structural properties and capacities in assuring timber durability and long-lasting fixing. This aluminium beam is made of an extruded profile with shape and size optimized for load-bearing capacity and lateral stability. Special grooves at both sides are designed to obtain fast and efficient fixing of shear-resisting plates and hold-downs. Main results from latest experimental campaign are given to characterize the system in terms of load-bearing capacity and case-study applications in newly-realized timber buildings are presented. Finally, a proposal for possible restoring intervention to replace the damaged timber at the base of the wall is hypothesized.

Engineered Aluminium Beams for Anchoring Timber Buildings to Foundation

This paper reports the structural characterization of an innovative engineered aluminium beam, used as bottom rail for timber shear walls, capable of overcoming the crucial durability problem that could affect the timber shear walls near the foundations, at the same time improving the precision and speed of installation. Traditional techniques have disadvantages such as excessive geometric inaccuracies, difficulty in achieving efficient and long-lasting solutions, compression orthogonal to the wood grain, reduced durability due to increasing dampness and problems with waterproofing. Results from laboratory tests conducted to verify the mechanical behaviour of this innovative bottom rail when subjected to tension and compression perpendicular to its axis are reported in comparison with numerical provisions. The ultimate strength of the aluminium-to-timber connections, specifically developed to be compatible with the beam and easily installable, was also obtained. The results demonstrate that this innovative technology ensures the achievement of the expected static performances. Installation and durability advantages are highlighted and the first utilization of the aluminium beam is illustrated.

Fracture Mechanics Models for Brittle Failure of Bottom Rails due to Uplift in Timber Frame Shear Walls

In partially anchored timber frame shear walls, hold-down devices are not provided; hence the uplift forces are transferred by the fasteners of the sheathing-to-framing joints into the bottom rail and via anchor bolts from the bottom rail into the foundation. Since the force in the anchor bolts and the sheathing-to-framing joints do not act in the same vertical plane, the bottom rail is subjected to tensile stresses perpendicular to the grain and splitting of the bottom rail may occur. This paper presents simple analytical models based on fracture mechanics for the analysis of such bottom rails. An existing model is reviewed and several alternative models are derived and compared qualitatively and with experimental data. It is concluded that several of the fracture mechanics models lead to failure load predictions which seem in sufficiently good agreement with the experimental results to justify their application in practical design.

Design against brittle failure of bottom rails in shear walls

The authors have developed a new plastic design method for light-framed timber shear walls, which is capable of analysing the load-bearing capacity of partially anchored shear walls. For proper application of the plastic method it is necessary to ensure ductile behaviour of the sheathing-to-framing joints and to avoid brittle failure of the bottom rail. In a partially anchored shear wall, the tying down forces are developed in the sheathing-to-framing joints along the bottom rail, which may introduce a brittle type of failure of the bottom rail that needs to be eliminated in order for the plastic method to be applicable. This paper deals with design of anchor bolts needed to tie down the bottom rail properly and it describes experimental results for proper design of washers for anchor bolts to avoid these splitting failures of the bottom rail. The effect of different washer sizes and location of the anchor bolts on the failure load when splitting of the bottom rail occurs is presented. The tests indicate that the failure load depends on the distance from the edge of the washer to the loaded edge of the bottom rail. An explicit design equation for the capacity of the bottom rail is presented.

Horizontal Stabilisation of Sheathed Timber Frame Structures Using Plastic Design Methods – Introducing a Handbook Part 1: Design Principles for Horizontal Stabilisation

The authors have developed a plastic design method for sheathed timber frame shear walls. It has been presented and discussed for inclusion in Eurocode 5 and a Swedish handbook has been presented. In the plastic method, you can choose to transfer the anchoring force via the leading stud to the substrate, corresponding to a fully anchored shear wall (no uplift of studs), but you can also choose to utilize the sheathings to transfer the tensile force via the sheathing-to-framing joints to the substrate by anchoring the bottom rail, corresponding to a partially anchored shear wall (studs experience uplift). By the plastic method several alternatives for anchoring the wall are possible and they can also be combined in such a way that each of them take a portion of the uplifting force, e.g. through a simple tying down device, through the sheathing-to-framing joints and through anchoring of the shear wall to the transverse wall. The method also makes it possible to include the load-bearing capacity of wall segments including openings. The handbook treats primarily shear walls, but for the sake of completeness some aspects of the roof and floor diaphragms are also discussed. The interior force distribution in sheathed timber frame walls weak in shear is discussed, as are the fundamental difference between the effect of vertical loads on the stabilisation of walls which are rigid or weak in shear, and how the plastic design method is applied to multi-storey timber buildings.

Analytical models for splitting capacity of bottom rails in partially anchored timber frame shear walls based on fracture mechanics

Plastic design methods can be used for determining the load-carrying capacity of partially anchored shear walls. For such walls, the leading stud is not fully anchored against uplift and tying down forces are developed in the sheathing-to-framing joints and the bottom rail will be subjected to crosswise bending, leading to possible splitting failure of the rail. In order to use these plastic design methods, a ductile behaviour of the sheathing-to-framing joints must be ensured. In two earlier experimental programmes, the splitting failure capacity of the bottom rail has been studied. Two brittle failure modes occurred during testing: (1) a crack opening from the bottom surface of the bottom rail and (2) a crack opening from the side surface of the bottom rail. In this article, a fracture mechanics approach for the two failure modes is used to evaluate the experimental results. The comparison shows a good agreement between the experimental and analytical results. The failure mode is largely dependent on the distance between the edge of the washer and the loaded edge of the bottom rail. The fracture mechanics models seem to capture the essential behaviour of the splitting modes and to include the decisive parameters.

Evaluation of softening behaviour of timber light-frame walls subjected to in-plane forces using simple FE models

The present investigation focuses on evaluating the entire load–displacement relationship, especially the softening part, of light-frame wall segments subjected to in-plane monotonic forces when the load-slip curves of the individual sheathing-to-framing fasteners are considered. Different sheathing-to-framing joint characteristics, including unloading behaviour, and stud-to-rail joint characteristics are incorporated in the analyses. Two loading cases are investigated: Horizontal loading resulting in uplift of the leading stud and diagonal loading representing a fully anchored wall.Two common types of finite element (FE) models for the sheathing-to-framing joints are used for the analyses: A single spring model and a spring pair model, where the joint characteristics valid for the timber properties perpendicular and parallel to the grain are used. The maximum capacity of the wall segments is somewhat overestimated when using the spring pair model compared to that of the single spring model. The softening parts of the load–displacement curves are significantly affected, regardless of whether the perpendicular or parallel characteristics of the joints are used.The results from FE simulations using models with perpendicular and parallel characteristics are compared with full scale test results for walls with a single segment loaded horizontally and diagonally. The behaviour of the wall segments subjected to horizontal loading is dominated by fastener displacements perpendicular to the bottom rail. Hence, FE models including perpendicular characteristics should be used. For diagonal loading the behaviour of the wall segments is dominated by displacements parallel to the framing members, and FE models including parallel characteristics should therefore be used.The analyses were extended to multiple segment walls resulting in the same type of behaviour as single segment walls.

Splitting capacity of bottom rail in partially anchored timber frame shear walls with single-sided sheathing

Plastic design methods can be used for determining the load-carrying capacity of partially anchored shear walls, where hold-downs are not provided. In order to use these methods, a ductile behaviour of the sheathing-to-framing joints must be ensured. Since the forces in the anchor bolts and the sheathing-to-framing joints do not act in the same vertical plane, the bottom rail will be subjected to bending and shear in the crosswise direction, and splitting of the bottom rail may occur. In this article, results of two experimental programmes on the splitting capacity of the bottom rail due to uplift in partially anchored shear walls are presented. Two brittle failure modes occurred during testing: (1) a crack opening from the bottom surface of the bottom rail; and (2) a crack opening from the edge surface of the bottom rail along the line of the sheathing-to-framing joints. The results show that the distance between the edge of the washer and the loaded edge of the bottom rail has a decisive influence on th...

Bottom Rail on Top: The Shifting Sands of Sustainable Development Indicators as Tools to Assess Progress

The Human Development Index (HDI) is often employed to capture some of the more social concerns in sustainable development at the scale of the nation-state. The HDI is founded on three components; life expectancy, education and income per capita. To avoid a dominance of the income component, proxied by Gross Domestic Product (GDP) per capita per annum, it has been capped at a maximum level and transformed. Two methods for transforming the GDP/capita have been employed; the Atkinson transformation (1991 to 1998) and the Logarithmic transformation (all other years). The paper explores the impact that these transformations have had on the HDI rankings of 167 countries, by comparing the rank across two periods; 1991 to 1998 and 1999 to 2009. Results suggest that for the 167 countries in the dataset, the majority (65%) showed a high resilience to the transformations. For these countries, the use of the two alternatives does not alter the difference seen in the original ranking between the two periods. A significant proportion of countries had a medium (18%) and low (17%) resilience to the methodology for handling GDP/capita. For those countries the choice of methodology does matter in terms of their ranking, with some doing better and others worse relative to the original ranking. Consistency in methodology is desirable in order to avoid such misrepresentations but so is some flexibility to allow for new knowledge and experience. One can also question the value of the league table style of presentation so often employed with sustainable development indices given that change in rank for at least some countries is so vulnerable to shifts in methodology.

Air Supply System Optimization for the Multi-Temperature Refrigerated Trucks

The multi-temperature refrigerated trucks which can transport a variety of goods at the same time, meet the requirement of production and marketing mode of “small production/big market” for Chinese agricultural products. In this paper, the multi-temperature refrigerated trucks with sidewall air duct and bottom return rail were selected to simulate the effect of air outlet locations and wind speed on the flow field of the carriage. The layout of the air outlet location and the wind speed was optimized accordingly.

Occupied Women: Gender, Military Occupation, and the American Civil War

Occupied Women, a collection of essays edited by LeeAnn Whites and Alecia P. Long, demands that women be integrated into the military history of the Civil War in a new way that obliterates the distinction between home front and battlefront. The title is a double entendre and reflects the book's focus on female actions in Union-occupied territory, as well as its central premise that women did more than simply respond to wartime disruption. According to Whites, they acted “not as the hapless victims of collateral damage of Union occupation or as the occasional and atypical politicized woman but as the critical bottom rail of the war of occupation” (p. 6). The occupied women in these essays come in many different forms, including elite Confederates in Natchez, Mississippi, and New Orleans, Louisiana; Confederate sympathizers in Union border states; and African American and white Union sympathizers in Confederate states. While women's occupation and their resistance took many forms, the authors in this volume all make convincing arguments that the particular women under consideration were not civilians trying to cope with war, but were combatants themselves. Long sets the tone in her fine essay on Benjamin Butler's General Order No. 28 when she asks: “What if the women in occupied areas … were the equivalent terrorists of their day—elusive, mercurial, hiding among the population but somehow slippery and uncontrollable” (p. 31).

Structural adequacy assessment of a disused flat bottom rail wagon as road bridge deck

This paper presents half of a full scale experimental testing technique for assessing the structural adequacy of a disused flat bottom rail wagon (FBW) for low volume, heavy axle load road bridge applications. The aim of this ongoing research project is to develop sufficient knowledge required for achieving significant economy and safety of the heavy axle transportation system in regional government council roads. In the absence of such knowledge, the viability of replacing/rehabilitating the ageing bridges could not be economically justified, mainly due to low volume traffic and the costs of alternate solutions using new materials for heavy axle load demands. This study describes a comprehensive laboratory testing of half of a single lane, single span bridge deck and an associated three dimensional finite element modeling. The novel idea in the paper is to enforce the transverse continuity conditions along the longitudinal edge of the half of full scale bridge so that the single FBW tested will mimic the behaviour of a double FBW deck for a single lane road bridge under heavy axle design loads. Several serviceability and ultimate load tests, conforming to the Australian bridge design traffic loads applied at critical locations of the FBW system are reported in the paper. The test results demonstrate that the FBW possesses sufficient structural strength and can service the required design traffic loads.

Plastic models for analysis of fully anchored light-frame timber shear walls

In order to stabilise timber-framed buildings against lateral loads, the diaphragm action of roofs, floors and walls is often used. This paper deals with plastic analysis models for fully anchored sheathed shear walls. The models are based on the assumption of plastic load–slip relations for the sheathing-to-framing joints. Only static loads are considered. The basic structural behaviour and assumptions for the plastic models are elucidated. Both upper and lower bound methods are applied. The load-bearing capacity and the deformation of the shear walls in the ultimate and serviceability limit states, respectively, are derived. Both a discrete point description and a continuous flow per unit length modelling of the fasteners are discussed. Also, the forces and displacements of the fasteners and sheathing are derived. The influence of flexible framing members and shear deformations in the sheets, and also the effect of vertical loads on the shear wall, both with respect to tilting and second order effects, on the horizontal load-bearing capacity and displacement are evaluated. The stress distribution and the reaction forces at the ends of the different framing members are derived. The elastic model is experimentally verified and an illustrative example is given. The main objective of this work is to contribute to a better understanding of the structural behaviour of these fully anchored walls and form the basis for establishing a new plastic design method for partially anchored shear walls, i.e. a design method capable of analysing the more practical conditions of no or partial anchorage of the studs and/or bottom rail in real structures.

Elasto-plastic model for analysis of influence of imperfections on stiffness of fully anchored light-frame timber shear walls

In order to stabilize timber-framed buildings against lateral loads, the diaphragm action of roofs, floors and walls is often used. This paper deals with the influence of imperfections such as gaps and uplift on the stiffness and the horizontal displacement of fully anchored shear walls. The significance of analyzing the effects of imperfections is evident when evaluating the stiffness of shear walls; tests of walls show that the horizontal displacement is underestimated in calculations using the stiffness of sheathing-to-framing joints as obtained from experiments. Also, in real structures where hold-downs are used, the influence of gaps and uplift should be included in order to obtain realistic displacements in the serviceability limit state. The analytical model is based on ideal plastic behavior of the mechanical sheathing-to-timber joints with stresses parallel to the perimeter of the frame and on linear elastic behavior for stresses perpendicular to the bottom rail. Using this elasto-plastic model, the equations for the stiffness and the deflection versus the number of segments in the wall are derived. The fully anchored condition for the shear walls is simulated by applying a diagonal load to the shear wall. Three types of imperfections are evaluated: Walls with gaps at all studs, a gap only at the trailing stud, and gaps at all studs, except at the trailing stud. It is shown that the effect of imperfections on the stiffness of the wall in the initial stage is considerable. Depending on the distribution of the gaps and the number of segments included in the shear wall, the displacement of the shear wall is increased several times compared to that of a fully anchored wall diaphragm with no gaps; e.g. for a single segment wall more than four times. However, for walls with more than six segments the effect of imperfections can be neglected. Finally, the theoretical model is experimentally verified.